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Mac OS9 Flood Attack

Yoel Inbar writes "John Copeland, a professor at Georgia Tech, has discovered the possibility of using Macs running OS 9 as a distributed DOS tool. Basically, by sending a Mac running OS 9 a custom UDP packet, you can get it to reply with a 1500 byte ICMP packet(these packets are normally sent as part of MTU discovery). Send these UDP packets to a bunch of Macs, spoof the source addresses....voila, instant DOS. Apparently this is "in the wild"; he reports several scans designed to elicit these packets. "

185 comments

  1. Re:Wouldn't that be quite difficult by olof_j · · Score: 1
    Now that is not completely true.

    The fact that you have to send as many packets as the recipient of the DoS attack is true, but from how I interpret the announcement, no matter how small the UDP packet is a 1500 byte ICMP packet will always be returned.

    This is a bit odd. Why 1500 bytes? It is the MTU for Ethernet, but I can't really see how that should affect the size of the ICMP error message. Maybe the fellows at Apple made an error in the internal coding of packet length, and the ICMP error-return code included the sent packet and then garbage up until the 1500 byte limit.

    However, it can never be as destructive as a smurf attack (unless you have a whole subnet filled with Macs running OS9 _and_ they answer with this ICMP on broadcast packets to the specific port). Also, if it is only one specific UDP port, it is pretty easy to block in firewalls.

  2. no -its acting like a byte amplifier by Kancer · · Score: 2
    One 44k packet gets amplified to one 1500k packet. From the site:

    Here I have three slaves (199.77.146.20, 199.77.146.103, 199.77.158.61) being stimulated to send 30 1500-byte packets per second to address 24.88.48.47 (my cable modem). The combined bit rate is 3 x 30/s x 1500 bytes x 8 b/B = 1,080,000 bits/s. I could have increased the rate several times, but not much more would have interfered with the network.

    -kris

    1. Re:no -its acting like a byte amplifier by Anonymous Coward · · Score: 0

      Here I have three slaves (199.77.146.20, 199.77.146.103, 199.77.158.61) being stimulated to send 30 1500-byte packets per second to address 24.88.48.47 (my cable modem). The combined bit rate is 3 x 30/s x 1500 bytes x 8 b/B = 1,080,000 bits/s. I could have increased the rate several times, but not much more would have interfered with the network.

      No wonder all those 24.x.x.x Quake servers have been so slow today!

  3. what's up with the Mac luser impersonators?!?! by Anonymous Coward · · Score: 0

    see above..wtf?! you gotta be a hoax! i don't believe you're real.

  4. Re:A new hacking tool? ;) by crimsun · · Score: 1

    Actually 9x is avoided. NT is, as you say, used "as little...as possible." I'm not one to vouch for the use of any Windows platform or Linux distribution, but I will say that I have never had a prejudice against MacOS, which seems like a secure enough OS from a network standpoint (notice that I did not include stable, however ;-).

    I, too, find it interesting that such attention is targeted specifically toward OS 9 when all the facts have yet to be laid out. And yes, it is correct that all OSes have the ability to react in the manner as in the original post.

    I will differ from you in that I believe OpenBSD is the most secure out-of-box solution. As for "easiest" to maintain, well... ;-)

    Oh, and these are my views, not the university's. =)

    Thanks,
    dtc

    (who is very pleased with his extremely secure stand-alone TI-30)

  5. Re:the Red Hat open source investment... by Beatles · · Score: 0

    Anyone who invests in any publicly traded company owns part of that company. That's the entire concept behind public trading.

  6. Problem averted by Anonymous Coward · · Score: 0

    If they had just released Rhapsody on time as was promised.

  7. Bugs and Slashdot by NII+Link · · Score: 1
    Well, I was about to put the URL of the patch to fix this in, but it seems that some people beat me to it (http://asu.info.apple.com/swupdates.nsf/artnum/n1 1559 in case those other posts are below your threashold).

    Anyway, I fail to understand why such an obscure bug has propted such heated responses. Bugs happen to everyone - Apple, Microsoft, and even Linux. Unfortunately, they are a fact of life. Programmers are only human after all. What puzzles me is that this story went up within hours of it first being written, while a story that I sent in several weeks ago that was Apple related (the HeaderDoc, Netsprockets announcement) was rejected within minutes only to be posted a while later.

    Not that I'm suggesting anyone has a double standard of course, I know it's hard to sift through hundreds of story submissions. Still...

    --
    -Rafi Remove the Spanish to email me.
  8. Re:Here's the gist of the scheme by mr_burns · · Score: 1

    This is not a new thought. Using many machines on many subnets to flood an IP in concert. This particular incarnation of this attack is just another straw in the haystack. Given knowlege if the functionality of a client's stack, you should be able to find a way to make it do similar things. Just spoof an IP and ping it....there's no genius to that. Using false return addresses has been a tool of the malevolent since people hung numbers on their caves. Actually, using one OS to do this is unwise because one patch or fix can foil all your plans. It is tactically more sound to use multiple OS's in such a scheme, so that if one OS fixes the problem, the others may still function properly.

    I'm just glad people still think these are ingenious means of attack. There are much more devilish ways to DoS.

    --
    "Let him go, Ralph. He knows what he's doing." --Otto Mann (simpsons)
  9. don't forget about us! by ddtstudio · · Score: 1

    we covered this story at MacWEEK pretty well, i thought.

    see for yourself

  10. Here is the fix: by crayz · · Score: 2

    Apple's servers seem to be down(coincidence?), but the fix should be right here:

    http://asu.info.apple.com/swupdates.nsf/artnum/n 11559

  11. There is a fix by Anonymous Coward · · Score: 0
  12. Re:Huh? by Anonymous Coward · · Score: 0

    Hi. I've never heard of Windows Update and I eat potatoes with my toes. I think that I'll post on Slashdot and tell everyone that Microsoft's TCP/IP stack hasn't change for 10 years.

    I'm a smart man, Charlie Brown.

  13. Re:Can we get more information by Rilke · · Score: 3

    The difference here is that I can trigger a response much larger than the request. If I send an ICMP ping of 1000 bytes, the response is going to be 1000 bytes.

    But with this attack, I can trigger a response of 1024 bytes by sending only 24 bytes. The idea being that I can fill the victims pipeline without filling my own.

    But for the most part that's just bogus. The difference in size just isn't that great. A script kiddie will fill his own ppp bandwidth with the triggers long before whitehouse.gov gets overloaded with the payload. Also, much of the bottleneck is due to # of packets rather than # of bytes, and the # of packets is identical for attacker and victim.

    Apple should fix the hole, but in the grand scheme of things this isn't huge security news, especially given the paucity of Mac servers on the Net (where this could really do some damage).

  14. Re:Here's the gist of the scheme by Megane · · Score: 2

    I think there would have to be an AWFUL LOT of Mac slaves to actually swamp a DS-3 connection. In fact, I bet it isn't even possible.

    You mean a lot of MacOS 9.0 slaves. How old is 9.0 anyhow? Three months? There is already a low enough population of Macs on the live-connected Internet for this to be difficult to exploit, but they also have to be upgraded to a three-month old OS, too! "I don't think so, Tim."

    --
    #naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
  15. Cert Advisory CA-99-17 by HiroProtagonist · · Score: 2



    Don't know if this is related, but here is a link to the Cert Advisory discussing how Mac OS9 can be used as a 37.5 times DoS amplifier.

    Hope this helps.

    --
    --Remove chicken to e-mail
  16. Re:Wouldn't that be quite difficult by mangino · · Score: 2

    How big is the ethernet frame that carries the 29 byte packet? 1500 bytes. This is a 1:1 attack. You could probably do twice as much damage if you just ping flooded from the unix box on the large pipe you rooted.

    True, you get a bit of a multiplier in the response, but this still isn't an attack with a multiplier. Its not like the mac sends the same packet back out to the broadcast address which then starts all the other macs doing this. It would be more effective just to ping flood them from the rooted box on the big pipe. Think about it, if you have rooted a unix box on a fat pipe to coordinate the attack, why not just attack from there?
    --
    Mike Mangino Consultant, Analysts International

    --
    Mike Mangino
    mmangino@acm.org
  17. Re:Since source is closed, we must wait for Apple. by Darchmare · · Score: 1

    Funny, consensus so far is that there isn't even a problem.

    - Jeff A. Campbell
    - VelociNews (http://www.velocinews.com)

    --

    - Jeff
  18. Fraud... by Anonymous Coward · · Score: 0

    This report seems totally bogus being that it is not on a Georgia Tech server, that Dr. Copeland is a physicist who does research on high speed optical networking, and he doesn't mention it at all on his personal webpage.

    1. Re:Fraud... by Anonymous Coward · · Score: 0

      I don't see any indication that anything else is going down

      ... and therefore you've proved that nothing is going down?

    2. Re:Fraud... by Anonymous Coward · · Score: 0

      assuming that your link to his personal page is valid, there's a link in his 'more' section... (unless the personal page is fake, too -- it's a conspiracy!)

    3. Re:Fraud... by Anonymous Coward · · Score: 0

      There's a link (More...) on the top of that page that goes to another Copeland gatech.edu page with the mac DOS attack described on it. However, that page (http://www.csc.gatech.edu/~copeland/) is on a different subnet that the other gatech servers I checked. Hmmm...

    4. Re:Fraud... by Anonymous Coward · · Score: 0

      I hate to interrupt your Grassy Knoll studies, but the reason it's not on the Tech servers is that the school is going off-line to ride out Y2K. Georgia Power is one of the worst power companies you can imagine--Old Southern incompetence at its worst. The solution was simple: completely shut down the school so spikes and outages don't fsck up the machines.

      Had you bothered to read his mediaone page closely, you would have seen these lines:

      The Georgia Tech network is being shut down over the Holiday break, so my normal email address and Web page may not be available.

      Now get back to work and give my regards to Oliver Stone.

      Idiot.

    5. Re:Fraud... by Anonymous Coward · · Score: 0

      The guy looks like he did something very bad and was involved with weird people.

    6. Re:Fraud... by Anonymous Coward · · Score: 0

      According to git.oit.availability (local newsgroup at GaTech), *Mordred* is going down for the holidays for an OS upgrade, security hejaz, and to play with "Y2K" issues. Mordred is the departmental webserver at Tech. I don't see any indication that anything else is going down (due to expected power problems or otherwise).

      Don't Panic.

    7. Re:Fraud... by blue · · Score: 1
      It is in fact on Georgia Tech server as well, witness http://www.csc.gatech.edu/~ copeland/macattack/index.htm.
      Also noted on both pages is:

      (note: Georgia Tech's network will be shut down from Dec. 30 until Jan. 4, 2000)

      Perhaps that's why he has it off-server as well. I would say it's authoratitive. (The report, anyway.)

  19. Re:I knew it. by Anonymous Coward · · Score: 0

    its a vast, antimac conspiricy to hold down the ultimate computing platform of all time!

    As we all know, the mac was perfect in 1984, and has since been getting more perfect. memory protection is for idiots who can't code worth shit.

  20. A Smurf by any other name? by jabber · · Score: 2

    How is this 'supposed' new DoS attack different from what we've already seen?

    Sounds simple in principle:
    Pretend to be your target (IP spoof)
    Ping a bunch of Macs
    Watch real target fall over as all the Macs respond to the ping

    How and why is this different? The 1500b packet? Is MacOS 9 unique in this?

    Pardon my ignorance, just really curious.

    --

    -- What you do today will cost you a day of your life.
    1. Re:A Smurf by any other name? by frankie · · Score: 1
      why is this different? The 1500b packet? Is MacOS 9 unique in this?

      No, it's basically the same. Other network devices that use Mentat's stream code, or similarly designed code, will also produce 1500b responses. The only thing that's vaguely new here is that previous to OS9, Macs were exceedingly unlikely to be used in flood attacks.

  21. I dont understand by konstant · · Score: 2

    I'm not very familiar with IP spoofing, but isn't this possible with every system everywhere all the time?

    If I sent ping packets with spoofed IPs to three hundred machines running any OS, wouldn't they respond with packets to the target machine?

    -konstant
    Yes! We are all individuals! I'm not!

    --
    -konstant
    Yes! We are all individuals! I'm not!
    1. Re:I dont understand by Natedog · · Score: 2

      your comment is more or less correct - assuming that there are no filters on the routers along the way. however, the big deal is that, according to this advisory, the OS 9 can be made to reply with a packet 37.5 times the request. If this is true, the OS 9 can be used as a "traffic amplifier." In short, if an attacker using a T1 set things up properly she/he could possibly flood a machine with ~37 T1's worth of traffic - enough to take out almost any site. It would be far better if it always replied with less data (thus becoming a deamplifier), but oh well.

      --
      \forall code \in C, \frac{\Delta readability(code)}{\Delta t} < 0
  22. "I Think You Missed the Point...It's the Joint"-BB by Anonymous Coward · · Score: 0
    1) The security note is NOT against OS9 Macs. Rather, OS9 Macs are enlisted (unwittingly) into being amps for a tribe-style assault.

    2) Look, this paradigm is old news:
    Old news about tfn
    Old news about trinoo

    3) This is just a tool to be used with next generation, distributed smurf program.

    4) Macs are not the problem. Instead, the problem is peeps who don't read carefully.

    5) Oh yea, moderate this down, fuckers. It's the truth, so bury it.

    6) Anyone get the subject line reference?
  23. apple's patch is up... by noy · · Score: 2


    well, this might be some 'hoax', but *someone* at apple posted a patch even though they seem to be off...

    this is really standard stuff, there are at least as many misconfigured routers out there (on biggger pipes) than static IP OS9 machines... i doubt the existence of ANY Y2K plot using these machines...

    anyway, the patch is at:

    ftp://ftphqx.info.apple.com/Apple_Support_Area/A pple_Software_Updates/English-North_Americ an/Macintosh/Networking-Communications/Open_Transp ort/OT_Tuner_1.0.smi.hqx

  24. Re:Macintoshes used for DOS? by Anonymous Coward · · Score: 0

    Not all Linux people are bright. It's the same kind of shit you bump into everywhere else...& this brings up another issue, Linux is great, blabla...but 10 million idiots don't justify one truth. As I see it, being able to execute a rather complex command on your system is perhaps good for people that demand that level of profundity, but for mere mortals it's rather irritating to use the terminal when you could have done your task otherwise, say a simple way... Most of the stuff you have to learn about Linux (as a nongeek) can be rendered superfluous. & this brings up another issue, Linux is way to much cracked up, for example: Mr. AverageJoe and Mrs. AverageJoe are about to choose a platform. As lucky as it turns out to be, Mr. AverageJoe happens to know about this real peace-love-and-compile-the-kernel guy next door. He asks this fellow about the greatest system and, of course, the answer is Linux, because it has all these advanced features and is free. Well it may be great for this geek because he can do it all by himself (look at me). Mr. AverageJoe returns home and embraces his wife; we are going to have some serious experiances with the CLI, Kernels blabla...and later Mrs. AverageJoe agrees, if it's recommended by a geek it have to be good. No, actually, that's the stupid part because, as it often occurs, the geek recommends what he thinks is exciting, not what's suitable for the given task(in this case, say, a simple tool to do surfing, writing & homework, for example...) I like Linux, but I would not recommend it to everyone, that would be too narcissistic. Well until someone can manage to put an proper UI with some basic Human Interface Guidlines it may be the panacea of all platforms... P.S "composing letters to idiots who don't understand that DoS is not DOS": Come on, give the guy a chance. You are better of learning someone something rather than telling them that they are idiots /JetEye

  25. I knew it. by rhinoX · · Score: 2

    Those macs are good for something.

    j/k

    --
    The copper bosses killed you, Joe. 'I never died', said he.
    1. Re:I knew it. by Anonymous Coward · · Score: 0

      Ya I am. If its crappy Apple coders or crappy Mentat coders, I don't care. The fact remains that the mac OS sucks. It is so obvious I don't know how ppl can stand it.

    2. Re:I knew it. by rabidMacBigot() · · Score: 1
      Let me go out on a limb here and assume that you're not flamebaiting, but honestly belive that MPS is somehow flawed. I don't think you truly realize the networking architecture that you're slamming here. Allow me to quote from Mentat's homepage:
      MPS is the native STREAMS on Apple Mac OS, Novell NetWare, Wind River VxWorks,Hewlett-Packard HP-UX, IBM AIX, Digital UNIX, and other many leading computer and embedded operating systems.

      And as for your conviction of the opinion (masquerading as "fact") that an intuitive, ergonomic, logically structured operating system is somehow flawed (as a client of course... Classic MacOS is a poor server), well... I sure wish you had some sort of coherent argument to back up your assertions, but hey, that's cool.

      We really ought to take this to email, to spare the rest of /., but since you're posting anonymously, I can't do that.

    3. Re:I knew it. by Anonymous Coward · · Score: 0
      As we all know, the mac was perfect in 1984, and has since been getting more perfect. memory protection is for idiots who can't code worth shit

      Yes sir; I'm glad you actually understand.
      As we all know, Linux was perfect in 1.0, and has since been getting more perfect. GUI's are for idiots who can't use a computer worth shit.

      PS: I know this is flamebait, but I'm having fun today! So just take a deep breath and don't be so serious.

    4. Re:I knew it. by Biff+Cool · · Score: 1
      Real men use punch cards and a difference engine. Everything else is just kruft.

      Conscience is the inner voice which warns us that someone may be looking.

      --

      Conscience is the inner voice which warns us that someone may be looking.
      -- H. L. Mencken

    5. Re:I knew it. by Anonymous Coward · · Score: 0
      Funny? Score 3? WTF?

      Its funny 'cuz we all know that macs are good for nothing. Now there is finally a use for one. Well, sorta a use since the lame MacOS can't even fill a 100Mbps network with traffic. Even 95 can do that.

    6. Re:I knew it. by blue · · Score: 1

      Perhaps if it had ANY relevancy to Linux AT ALL. Plus, get this: it was a joke. No non sequiturs please, ACs. Thank you.

    7. Re:I knew it. by Anonymous Coward · · Score: 0

      Funny? Score 3? WTF?

    8. Re:I knew it. by rabidMacBigot() · · Score: 1

      You realize that by saying that the MacOS can't saturate a 100Mbps network (though I'm not sure where your citation is), you're saying that Mentat Portable Streams can't saturate a 100Mbps network, right?

    9. Re:I knew it. by Anonymous Coward · · Score: 0
      Actually, they meant "Flamebait (-1)". But you know how stupid these antiMac moderators are.

      Anonymous Kev

    10. Re:I knew it. by Anonymous Coward · · Score: 0
      Let's see. If this had been a Linux problem, would the comment I knew those Linux boxen were good for something have rated a "Funny" ?

      I thought not.

      I'm not all that big on Macs, but the moderators should try to show some fairness. Further examination shows that there's a good chance this really isn't a problem. The source looks like a Y2K-Paranoid.

  26. DOS by technos · · Score: 2

    Now you can say to someone, 1930's gangster-style, that you're going to iWhack them.

    I can see this kind of distributed DOS being called the 'iWhack Attack'.

    --
    .sig: Now legally binding!
    1. Re:DOS by storem · · Score: 1
      According to this professor it's a iWhack conspiracy against the connected world as we now it in this millenium :-)

      (website excerpt)
      This page presents evidence of a conspiracy to shut down Internet Connections. Zero-hour is probably New Years Eve, EST.

    2. Re:DOS by Anonymous Coward · · Score: 0

      The guy is a prof here at tech. He's no more of a quack than your average professor. (interpret that how you will) =)

    3. Re:DOS by stimuli · · Score: 1
      All this Y2K on his site makes me think this guy is some sort of quack. I haven't seen anything about this exploid on Bugtraq yet, but maybe it is queued up.

      Does anyone have any verification of this besided what is on that page?

    4. Re:DOS by technos · · Score: 1

      Anyone got a LAN full of iMacs? I was wondering the same point; credibility of the otherwise paranoid author. If it were true, (And I assume it is) the Skr1p7 K1dd1eZ will truly have a field day.

      --
      .sig: Now legally binding!
    5. Re:DOS by doce · · Score: 1

      our ad agency is almost exclusively macs, and with our current growth, we have quite a few new iMacs and G4's running OS 9. We've been playing with this all afternoon, and haven't had a hiccup.

      --
      woof!
  27. Probably not unique to MacOS by Anonymous Coward · · Score: 1

    Many systems, when they receive UDP packets on an unbound port, will reply to the source address with an ICMP Port Unreachable message. One of the RFCs recommends rate-limiting ICMP messages. Apparently, Apple (or their supplier) didn't implement this suggestion.

  28. the microsoft investment... by kevin+lyda · · Score: 5

    apparently included in the ms investment, ms gave apple "some really good tcp/ip stack programmers."

    --
    US Citizen living abroad? Register to vote!
    1. Re:the microsoft investment... by IntlHarvester · · Score: 1

      I know it's a joke, but I believe Apple's TCP/IP stack was developed by Mentat, so other OS's TCP/IP stack may also be vulnerable.
      --

      --
      Business. Numbers. Money. People. Computer World.
    2. Re:the microsoft investment... by BadERA · · Score: 1

      is this a stack issue, or a higher level software issue? the patch Apple offers is specifically for Open Transport 2.5.2 ...

      --
      I am, therefore you think.
  29. this is no big deal. here's why: by enum · · Score: 1

    1. OS 9.0 didn't sell well.
    2. There aren't many mac users with cable modems because we are all poor from buying overpriced hardware.
    3. See #1 and #2

    no big deal.

    1. Re:this is no big deal. here's why: by _GNU_ · · Score: 0

      Cable (ethernet in my case), is *loads* cheaper than modem in sweden, and.. try to put together a quality pc for the price of a highend G4.. yah, you might be able to get the same or slightly below that price, if you don't buy 3:d party "stuff" from all over the place, and don't even mention celeron :P and how about warranty on that box? (not that I've ever needed my warranties, as I've been a mac user since 87..)
      Cya.

  30. A new hacking tool? ;) by crimsun · · Score: 2

    Wow, I never thought of using an OS's built-in networking code against itself, but heck, this sounds neat-O!

    Really, this is a serious security issue. As an admin, I rue the day that OS9 is deployed if such a possibility remains "in the wild." Being stuck in the middle of AOL's subnet doesn't help, either, but at least eliminating this one source will save myself and countless others the hassle of hoping and praying that no script kiddie gets his hands on a tool to exploit this vulnerability.

    1. Re:A new hacking tool? ;) by barbaBob · · Score: 3
      I take it that you don't deploy Windows 95, 98 or NT either because of the vulnerabilities that those particular operating systems have, especially in networked environments?

      What strikes me as a bit weird is that whenever the MacOS operating system has such a vulnerability everybody is going ballistic, like if it proves a point they have been making all along. Might be my peculiar way of looking at things tho :)

      I've been working with all three operating systems for quite a few years now, and MacOS - at least up to 8.6 - remains the most secure out-of-the-box operating system out. A well tuned and maintained Mac server remains one of the most secure internet platforms out there. Is up and running in less than a minute, a snap to set up and maintain.

      Of course, it has purposes it's best suited for and situations you'd rather not use one. Same goes for Linux, or any other operating system out there. Which is why I use MacOS, Linux and IRIX, and as little NT as possible :)

      Cya
      bBob

      (who is very happily running a mixed MacOS/Linux setup)

      --

      --
      *sig*

    2. Re:A new hacking tool? ;) by Caradoc · · Score: 1

      Exactly what I was thinking. I'm sitting here in the middle of three Linux machines (one's an Alpha) and two Macs. Strange that I haven't seen this kind of outcry about the morons on the various @Home networks that leave their Wintel machines open for mail relaying, or the widespread use of Back Orifice on those same networks to base secondary attacks. We're not talking about a "vulnerability" here - we're talking about the fact that an attack can be "relayed" due to a flaw in the way that the Mac OS implements the Mentat Streams. I know where there's a Mac IIsi running AIMS that's had *zero* downtime for the past 27 months, with one exception - they shut down the power to that closet without telling anyone, and the UPS kept it going until the bitter end. As soon as the power came back on, it brought itself back up and kept right on going. Were anyone to examine the percentages, I think they'd find that Windows machines (of *all* flavors) present a much greater and much more widespread threat in "relaying" attacks such as this.

      --
      Specialization is for insects. - R.A.H.
    3. Re:A new hacking tool? ;) by Anonymous Coward · · Score: 0

      wow, the grits meme has mutated.

    4. Re:A new hacking tool? ;) by Anonymous Coward · · Score: 0

      've been working with all three operating systems for quite a few years now, and MacOS - at least up to 8.6 - remains the most secure out-of-the-box operating system out.

      Security through rarity.

  31. BSD stack "inspires" Win2k? by Anonymous Coward · · Score: 0
    If this is true, let me make the following statement as a fan of the BSD license:

    Millions of potential Win2K users now have a good TCP/IP stack built on time-tested, battle-hardened code. Good. If they used BSD code, they've made computers suck a little less for everybody, and that means we all win.

  32. Re:You're a troll in disguise.. by Anonymous Coward · · Score: 0

    Wow, you Lunix people must be smarter than I thought! :)

    Kudos for catching onto the joke (w/ 100% accuracy -- was using Windoze at that moment). Too many /. readers, unlike you, only have that lame quasi-intellectual wit derived from Piers Anthony, Star Trek, and Asimov, if they have one at all...

  33. OT Advanced Tuner by waldoj · · Score: 3

    I believe that this 3rd party patch may permit you to change your OT settings to prevent this.

  34. Engineers on vacation. by Spax · · Score: 2

    Apple engineers and beta teams are on vacation until January 3. I don't know if this has already been addressed in the next patch to MacOS 9, but I guess they'll fix it now that it's known. Does this work in older versions of the MacOS?

    1. Re:Engineers on vacation. by Anonymous Coward · · Score: 0

      seems to also be relevant to the version of OT that came with G4's and slot loading iMac's that were shipped with MacOS 8.6 http://asu.info.apple.com/swu pdates.nsf/artnum/n11559

    2. Re:Engineers on vacation. by frankie · · Score: 1
      Does this work in older versions of the MacOS?

      No. As far as Macs are concerned, this bug is specific to the version of OpenTransport in OS9.0

  35. Re:Huh? by technos · · Score: 1

    Hmmm.. I'm running of the RC2 and 3 in a variety of roles. (I kept the early machines 'cuz I'm lazy and the bugs are pretty much worked around) While I'm not primary support for those machines, I haven't heard of this flaw. As we plan on 'early adopting' W2k, and I'm unlikely to get a straight answer from Microsoft, do you have any further detail?

    --
    .sig: Now legally binding!
  36. A patch is now available by vaxheadroom · · Score: 1

    Apple posted a patch to the Open Transport Stack on its web page at
    Open Transport Tuner 1.0. You may also find more information on the Mac Attack FAQ.

  37. iMac on Crack by Duxup · · Score: 2

    "Help! My iMac is on UDP crack!"

  38. Re:the Red Hat open source investment... by Anonymous Coward · · Score: 0

    have you ever heard someone say: "that was funny the first time?" Now perhaps you understand why your unoriginal post won't be moderated anywhere. But you can keep believing in a vast anti-mac conspiracy if it makes you happy.

    I'm glad to see that Amiga Persecution Complex is still alive and well.

  39. Which no one will install by Greyfox · · Score: 2

    No one ever installs those things. If every ISP filtered packets originating in the ISP with source addresses outside the ISP, smurf attacks (And several others) would be eliminated, too. The reasons are the same -- sheer ignorance. Bummer.

    --

    I'm trying to teach myself to set people on fire with my mind... Is it hot in here?

  40. What Evidence Points to 12/31/99 as the Date? by Anonymous Coward · · Score: 0

    I've scanned most of the documents in the various links, but I'm curious: where exactly is the evidence for the 12/31/99 attack?

    I mean, is this guy just speculating on the date or is there specific evidence for the New Year's Eve attack?

    If he's just speculating on the date, I can't imagine a more irrsponsible thing to do.

    This guy's a professor at Georgia Tech? Christ, this guy's a cuckoo. He sounds like one of those wackos determined to author the end-all paper on cold fusion -- or maybe author the end-all paper on a unified theory of everything.

    F$^king wacko academics.

  41. Re:Can we get more information by kijiki · · Score: 2

    yeah, except the ICMP_ECHO_REPLY is the same size as the ECHO_REQUEST you sent. Go read the good prof's write up. It points out that a 29 byte packet gets a 1500 byte reply. So your 33.6 modem could easily fill a T1. Try that with ICMP_ECHO.

    Its not as bas as smurf was, but don't write this off.

  42. Re:Apple's Statement by Jawbox · · Score: 1

    Aparently this attack is real, at least it is mentioned at cert.org under the distributed DOS attack section. However, all this conspiracy y2k talk on Prof. Copeland's site seems overdone. CERT terms this a 'traffic amplifier' in the sense that a small amount of bandwith can create approximately 37.5 times the bandwith spent. From CERT on Dec 28th: "For the "Mac Attack" Apple is developing a patch, as described in Appendix A. This advisory will be updated when the patch is available. "

  43. Huh? by Anonymous Coward · · Score: 0

    The original note is pointing out a weakness in the Microsoft TCP/IP stack??? What, specifically? The only weakness is see there is a miserably failed jump to a conclusion.

    BTW, since Windows is not open source, how do you really know it hasn't changed in 5 years? Is that another leap of faith also?

    1. Re:Huh? by Mr.+Flibble · · Score: 1

      BTW, since Windows is not open source, how do you really know it hasn't changed in 5 years? Is that another leap of faith also?

      Check out my reference to Phrack 54.

      --
      Try to hack my 31337 firewall!
    2. Re:Huh? by Anonymous Coward · · Score: 0

      Looked there, couldn't find it. Is there a specific quote from a specific article that you'd like to use? Something that says that they've examined the source code and that it is unchanged in the last five years? Or, are you saying that the nmap fingerprint is the same, therefore nothing has changed?

    3. Re:Huh? by Mr.+Flibble · · Score: 1

      I am saying that since that the fingerprint is the same that this is the best comparison that we have. If Microsoft does not have to change the code, then they probably won't as reusing old code is more cost effective.

      From my own perspective: Quake 3 Arena runs at a lower ping under Linux than it does under Win 98. My pings (to my close local server) average around 60-100 ms under windows. They average 30-60 under Linux. Same hardware (I dual boot).

      There is also probably a good deal of junk in the windows stack. This is why there are net-accelerators for windows. Again, I get faster download speeds under Linux (Cable modem) than I do under Windows. True, it could be tied to something else, but what? Given the number of times that I have installed (and Re-installed) Windows, and the times that I have upgraded my Linux Kernel and distro over the past few years, the pings and downloads are always better under Linux. You are correct, I can't prove its the stack. I just have very strong suspicion that it is. Is that enough to base an argument on? Probably not. Still I would be interested as to your thoughts on what could cause the difference.

      Regarding the first response, I still don't see how Red Hat is an equivalent, they don't control the TCP/IP stack under Linux, Microsoft obviously does under Windows. Microsoft has had its stack attacked many times, and is slow to fix it. The same attacks have been levied at Linux (just as this Mac DOS attack is being discussed) and the fixes have been extremely fast.

      My question is what is your point? The original post was funny, especially to myself as I have dealt with both OS's for some time. Microsoft DID make a "donation" to Apple. AFAIK, Red Hat did not. (And why post as AC anyhow?)

      --
      Try to hack my 31337 firewall!
    4. Re:Huh? by technos · · Score: 2

      In short: Several products have been developed that use the delays and incongruities inherent to any TCP/IP stack to try and 'fingerprint' the OS. Nmap, for example, can tell the difference between Linux 2.0.xx, patched 2.0.xx, 2.1.xx and 2.2.xx. The TCP/IP stack only changed slightly between kernels, yet there is a discernable difference. None of these products, however, can sniff out one iota of difference between the Chicago, Win95, Win NT 4.0, Memphis or Win98 TCP/IP stacks. Why? They're the same! No change. Additional evidence: Notice how each and every one of the Microsoft OS's is/was vunerable to the same 'nuke' type attacks? This is very unlikely if they do not consist of the exact same code.

      --
      .sig: Now legally binding!
    5. Re:Huh? by Anonymous Coward · · Score: 0

      From my own perspective: Quake 3 Arena runs at a lower ping under Linux than it does under Win 98. My pings (to my close local server) average around 60-100 ms under windows. They average 30-60 under Linux. Same hardware (I dual boot).

      Funny, I get a ping of 8ms in Win2k, but 37ms in Linux.

    6. Re:Huh? by TheGreek · · Score: 2
      Additional evidence: Notice how each and every one of the Microsoft OS's is/was vunerable to the same 'nuke' type attacks?

      Nope. There was an "issue" with Win98 and one of the Win2K betas or RCs and IGMP floods. They'd cause a bluescreen in the affected versions of Win98 and Win2K, but didn't in Win95 or NT4.

    7. Re:Huh? by Mr.+Flibble · · Score: 1

      Hm, cool. I have not tried Win2k. I don't know if I will. As I said, I did not know about the stack in Win2k, I guess they improved it.

      I am not a Linux zealot by any means, I just like this OS (Linux). Then again, I like BSD and BeOS too. To each their own.

      --
      Try to hack my 31337 firewall!
    8. Re:Huh? by Anonymous Coward · · Score: 0

      Yeah, I wish I could try it out in BeOS...their networking is not the /best/, but it would take advantage of my dual processors (need a bios update from Soyo before it'll work SMP mode under Win2k). Unfortunately BeOS doesn't support the ATM card either...so no network unless I drop down to 10Mbit ethernet...

  44. Re:Pardon my ignorance, but... by demon · · Score: 1

    It means "denial of service"...

    --

    Sam: "That was needlessly cryptic."
    Max: "I'd be peeing my pants if I wore any!"
  45. Re:Can we get more information by mangino · · Score: 2

    Just in case you read this later, my mistake. The 29 byte UDP packet problem is still correct with a min transfer unit of 64 bytes, the smallest you can send is 64 bytes. Too much time looking at ATM : )

    Thanks for setting me straight.
    --
    Mike Mangino Consultant, Analysts International

    --
    Mike Mangino
    mmangino@acm.org
  46. This is "informative"? by Anonymous Coward · · Score: 0

    It's full of misinformation and it's clear that the person didn't read the article, yet some retard moderator(s) thought it contained useful information?

  47. Re:I could have told you that one. by mcc · · Score: 2

    > Seriously, when has Apple's reaction ever been anything but "We have no official comment at this time"?

    when they have something to say.
    apple is not going to comment until they know exactly what is going on and have a patch.

    if you'll notice and read some of the posts put up after yours, you'll discover that once apple did know what was going on and had a patch.. they commented and released the patch.

    as for the apachebench bit, i think they did comment very quickly. i seem to pretty clearly remember reading a technote at apple's website about it. in fact i think that was where i first saw it, linked from macnn. i searched the Tech Info Library just now (which may not be the same as teh technotes) and was not able to locate what i thought i rememebred reading, but i did locate http://til.info.apple.com/techinfo.nsf/artnum/n590 05
    which is a general OS X Server patch that seems to adress the apachebench problem.

    i remember when the ping of death became a problem, but it was long enough ago i can't remember how apple handled it.

    apple does not like to do anything unless they can be sure of what they're doing. they do not like releasing software before they think it's perfect. they do not like talking about unreleased software until they're certain it's ready to be talked about. they do not like to comment on things they don't know enough about to comment on correctly. this seems pretty reasonable to me-- at least, it's slightly better than vaporwaring and amplifying rumors based on information they haven't personally verified yet.

  48. Note: Also affects some MacOS 8.6 -more- by Anonymous Coward · · Score: 0

    Apple's patch for the problem is out and the readme claims it's not only for all PowerMacs running MacOS 9 --as well as-- MacOS 8.6 systems --if-- it's running on a PowerMac G4, iBook, or second-generation iMac (with a slot-loading CD or DVD drive). Perhaps stock MacOS 8.6 on those machines contains MacOS 9's TCP/IP stack.

    Readme:
    http://asu.info.apple.com/swu pdates.nsf/artnum/n11559

    If this isn't an example of a need for broader opensource, I don't know what is.

    1. Re:Note: Also affects some MacOS 8.6 -more- by Anonymous Coward · · Score: 0

      It sounds like Apple included the newer OT with the OS 8.6 on the G4, iBook, and iMac DVs.

  49. Mac OS 9 and DoS by chocky · · Score: 1

    Apple has posted the TO Tuner 1.0 patch.

  50. Re:Apple just released OT Tuner 1.0 by Anonymous Coward · · Score: 0

    Ahh..props to Apple. How long would it have taken Microsoft to develop a patch? Linux users around the globe love to brag about how when a major bug is discovered, a patch is made available within hours. Same deal here.. and the engineers were on *vacation*... MAJOR props to Apple.

  51. re: trin00 / TFN is much more of a problem by larva · · Score: 1

    look, all of the distributed DOS systems require a machine to run on, which makes the fact that it can be used to flood pretty irrelevant compared to what else it can be used as.

    The OS9 thing is a networkcode issue, just like smurf attacks was. Whenever you design network code think about this: if the protocol being used does not use a handshake or in some other way verify the recipient, do NOT send large packets in response to small ones.

    UDP & ICMP/IP can be used for this sort of attack very easily. if you use a clever DNS request I'm sure you can get a packet back that is a lot larger than your request. connectionless protocols all have that flaw.

    On a last note though, this does not sound like a problem worth attention unless it responds to broadcast addrs.

    --
    -- gunzip-howto.tar.gz
  52. From the CERT advisory: CA-99-17 Denial-of-Service by Brian+Knotts · · Score: 2
    Asymmetric traffic from MacOS 9

    MacOS 9 can be abused by an intruder to generate a large volume of traffic directed at a victim in response to a small amount of traffic produced by an intruder. This allows an intruder to use MacOS 9 as a "traffic amplifier," and flood victims with traffic. According to [3], an intruder can use this asymmetry to "amplify" traffic by a factor of approximately 37.5, thus enabling an intruder with limited bandwidth to flood a much larger connection. This is similar in effect and structure to a "smurf" attack, described in

    http://www.cert.org/advisories/C A-98.01.smurf.html

    Unlike a smurf attack, however, it is not necessary to use a directed broadcast to achieve traffic amplification.

    and

    Appendix A. Vendor Information Apple Computer We've reproduced the problem in our lab and we are working now to create a fix that can be easily distributed to our customers. The problem only affects customers running our most recent release of networking software on machines that are continuously attached to the internet.

    While most Macintosh customers are not affected by this problem, we are moving quickly to put a solution in place.

  53. Re:Can we get more information by mangino · · Score: 1

    Umm, wrong. First of all, you can't send a 29 byte UDP packet. Second of all, it is carried on an ethernet frame to the cable modem which is 1500 bytes. You would need to have an incredibly thick pipe to actually do much damage. Remeber, the bandwidth is used at the ethernet layer. A 29 byte udp packet still uses 1500 bytes of bandwidth.
    --
    Mike Mangino Consultant, Analysts International

    --
    Mike Mangino
    mmangino@acm.org
  54. Re:CERT Advisory by Anonymous Coward · · Score: 0

    I got ~ 51x amplification. (1500/29).

    And the y2k conspiracy was a joke. better put sarcasmd (8) back in your init scripts.

  55. yippeeeeeeee by Anonymous Coward · · Score: 0


    I'm gonna go out and buy a buncha mac's with OS9 so I can start DoS'ing people!

  56. Re:Here's the gist of the scheme by Anonymous Coward · · Score: 0

    You had to search the web for this? I clicked on the link given in the article, and then clicked on "MacOS DOS attack"

    Either someone updated this story or you're a fucking moron.

    Or maybe just trolling for karma.

  57. Re:Sounds like a Smurf attack. by larva · · Score: 1

    >What I'm asking is why don't more places prevent 1.1.1.1 from sending out a spoofed 2.2.2.2 packet?

    I'm afraid the only answer to that is ignorance. Nothing will break, after all - the protocol suite is intended to work with "real" addrs.

    --
    -- gunzip-howto.tar.gz
  58. Re:trin00 / TFN is much more of a problem by platypus · · Score: 2

    While you are right in saying that trin00/TFN is a big problem, on has to remark, as you say yourself, the attack you mention needs a cracked box.
    Show me ten boxes you have rooted (not your own please :)), and I'll give you the IP-Adresses of 20 Macs with OS 9.

  59. OS 9 Open Transport Issues by dyskordus · · Score: 1

    I do tech support for a largeish ISP. Apparently there is something majorly wrong with Open Transport in OS 9.
    In fact we have not yet been able to get a single customer connected who is running it.
    All of you mac people using modems to connect to the net may want to hold off until they get this one fixed.

    --
    "Reality is less than television."-Brian Oblivion
    1. Re:OS 9 Open Transport Issues by LMariachi · · Score: 1

      Sounds like something's "majorly wrong" with your ISP, as I've set up dozens of OS 9 machines to connect to various dialups and haven't had any OT issues.

    2. Re:OS 9 Open Transport Issues by dyskordus · · Score: 1

      People get connected, but then they get the unable to create network socket connection error from netscape.

      --
      "Reality is less than television."-Brian Oblivion
  60. Re:Boycott John Copeland! by jburstein · · Score: 1

    1. Have you looked at the patents referenced, or have you merely decided that they're "obvious" based on the titles? 2. Did you even bother to look at the dates for the patents that you quote? I'd imagine that both of these patents were issued well before you were even born...

  61. Re:I could have told you that one. by rabidMacBigot() · · Score: 1

    I heard about the MacOS X Server/Apache issue too. And if I recall, attempts were made to replicate the problem by numerous third parties, with no results. While I do not deny that an HTTP server locking up an operating system is inexcusable, the fact that few people seem to be able to replicate the issue makes it seem rather less virulent than ApacheBench crashing any MacOS X server it on which it was run.

  62. But: they already have: by BonzoDog · · Score: 1

    See here.

    Now, that didn't take long, did it?

  63. offtopic by jbarnett · · Score: 1

    I am warning you right now this is offtopic, but related.

    What methods are avaiable to stopping to slowing down this type of attack towards a Unix server? Would a firewall help, or could it be blocked at the router?

    This type of attack has been avaiable to crackers for awhile now, but I haven't seen a decent method of preventing, stopping, or even slowing down this type of attack? Any ideas?

    Could this be addressed in a ask Slash? It also burns when I take a piss, could this be addressed also?

    some of this is a joke, can you guess which?

    --

    "`Ford, you're turning into a penguin. Stop it.'" -THHGTTG
  64. What "OS 9 Open Transport Issues" ? by Duck0987 · · Score: 1
    I am just curious as to what issues you are having with your mac users. I also do mac tech for and ISP, and have not found a single problem in the few OS 9 boxes I have set up.

    Personally my b&w g3 running OS 9 that I am on right now via modem was a breeze to set up, and I haven't had a problem with it.

    Duck`

  65. Re:Boycott John Copeland! by Anonymous Coward · · Score: 0
    have you merely decided that they're "obvious" based on the titles?

    Doofus. Apparently no one bought you a clue for Xmas. It's called "sarcasm".

    Copeland's patents are pretty abstruse, but I still think his Mac warning is way overblown.

  66. Pardon my ignorance, but... by kdgarris · · Score: 1

    What does DOS stand for in this context?

    1. Re:Pardon my ignorance, but... by Anonymous Coward · · Score: 0

      DoS means "Denial of Service"--e.g., flooding a machine with ping packets (that it must respond to), and thereby exhausting its bandwidth, so nothing else gets done.
      This is very similar to DOS, an "operating system" provided by Microsoft under the name "Windows".

      Both DOS and DoS prevent you from getting work done. ;)

    2. Re:Pardon my ignorance, but... by Anonymous Coward · · Score: 0
      Disk Operating System.

      You see, some evil bastard has found out how to attack a Mac and turn it into a DOS machine. It could bring down not only the Internet, but graphic publishing shops worldwide. It's evil, I tell you, pure eee-ville!

      Hint to addled moderators: This is Funny.

  67. Re:Can we get more information by Hackboy · · Score: 2

    The problem is that the script kiddies crack a few hosts sitting on T1s or better and then run the attack from there.

    You might check out CERT's paper on distributed DoS attacks. They don't go into great detail, but it does explain how the kiddies operate.

  68. Re:not just a Mac OS 9 problem by Anonymous Coward · · Score: 0

    A modem user could take down a T1 with this. tell your buddy geoff to check his facts and read the prof. copeland's article.

  69. Sounds like a Smurf attack. by Rakarra · · Score: 2
    This type of thing (bandwidth amplification) is really not new at all, and it's for that reason that I'm a little surprised that OS 9 would be vulnerable. What do you get when you ping the broadcast address of a subnet using a spoofed IP? Bandwidth multiplication of up to a few hundred times. There have been router (and other) fixes for some time that prevent someone from being the middleman, but the picture of inattentiveness painted by this issue is not a pretty one, considering so many places are still vulnerable to being middlemen.

    Here's my question: Why aren't more ISPs filtering out IP packets that have a "From" address of a machine not covered by the ISP? If a router services an ip block of... say... 192.168.0.*, why doesn't it drop packets that don't come "from" that address? I suppose the big question is, why is address spoofing even an issue anymore? Is there some sort of roaming technology that might break? Can someone point out what would be back about this?

    1. Re:Sounds like a Smurf attack. by Anonymous Coward · · Score: 1

      Some (most?) of us do filter packets that come into our routers that have a source address of our internal network. This is not the issue. The attacker is forging his source address to be the address of the target, and uses a 3rd middle man as the amplifier. So we have 3 people: 1.1.1.1 is the attacker, 2.2.2.2 is the middle man, and 3.3.3.3 is the target to be attacked. 1.1.1.1 sends spoofed 40 byte UDP packets to a macintosh at 2.2.2.2. The spoofed address is 3.3.3.3 (the target). The mac sends the 1500byte ICMP responses to 3.3.3.3 (the target).

    2. Re:Sounds like a Smurf attack. by Rakarra · · Score: 2
      Some (most?) of us do filter packets that come into our routers that have a source address of our internal network.

      Yes, and I would certainly call that a "good thing," but that's a little different from what I was asking. You're refering to preventing a spoofed 1.1.1.1 packet from entering the 1.1.1.1 network. What I'm asking is why don't more places prevent 1.1.1.1 from sending out a spoofed 2.2.2.2 packet? 2.2.2.2 isn't on that network, so why shouldn't packets heading out "from" those addresses be blocked? I'm trying to think of a legitimate reason for allowing these false from addresses in IP packets, but I can't at the moment.

  70. DOS means Denial Of Service. by rhinoX · · Score: 1


    See above.

    --
    The copper bosses killed you, Joe. 'I never died', said he.
  71. Re:Wouldn't that be quite difficult by beme · · Score: 1

    There I go again, believing things I read. :)
    I hadn't considered the size of the ethernet frame, but then again, I'm not the type of guy that has the knowledge to consider things like that.
    The reasoning not to just ping flood them from the rooted box is apparently this (from that link):

    If the attack computer sends 4000 40-byte trigger packets per second
    (bit rate less than 1.3 Mbps), the slave will send 4000 1500-byte packets
    to the target (bit rate 48 Mbps).

    The target organization (or organizations) is cut off from the Internet
    because it's connection, a 1.5 Mbps (million bit per second) T-1 or a
    45 Mbps DS-3 digital line is swamped with ICMP packets from forty
    different sources. Note that 30 different T-1 connections could be
    swamped by varying the return addresses in the trigger packets).

    Does this make sense? I'm no guru (or neophyte, for that matter), but it sounds like you're saying this guy's "byte amplification" is a load of hooey because the ethernet frame for the little trigger packet is still 1500 bytes, so you're using up your bandwidth whether or not you fill up the frame. (wonderful feeling to knowingly display a lack of knowledge on /. ;))
    I'd agree that this seems like an odd method to launch a DoS attack. Except that it's kind of cool (if it's true).

    -beme

    --

    -beme
    1971
  72. Very likely to be a hoax... by _GNU_ · · Score: 1

    Could anyone really take that guys site for real?
    "evidence of a conspiracy to shut down Internet Connections", yeah, right..
    It does seem on the page as if he is pro-mac, so I have no idea why he would post this.. but who knows what mental state he is in :)

  73. Re:the Red Hat open source investment... by barleyguy · · Score: 1

    I'm not sure about the quality of the stack in Win2K, but I remember reading that it had essentially an identical signature to BSD's. My theory is that the Win2K TCP/IP code is "inspired" by the BSD source code. So maybe that means it's actually decent.

    --
    --- "So THAT's what an invisible barrier looks like!" - Time Bandits
  74. I could have told you that one. by Zico · · Score: 1

    Seriously, when has Apple's reaction ever been anything but "We have no official comment at this time"? Remember how long Macs were susceptible to the Ping of Death a few years back? Silence from Apple. ApacheBench crashing any MacOS X Server that it touched, possibly pointing to an architectural flaw? No comment. No offense to you, John (I'm not sure if you work for Apple or not), but Apple seems to be near the bottom of the list -- at least they're above Oracle -- when it comes to releasing critical information in a timely manner.

    Cheers,
    ZicoKnows@hotmail.com

    1. Re:I could have told you that one. by _GNU_ · · Score: 1

      They did fix the cgi flaw in OS X Server quickly enough.

  75. exactly by Asparfame · · Score: 1

    Compounded with the fact that first you have to make a list of several Macs with the bug who's total bandwidth is at least equal to yours, otherwise you are being no more effective than a ping flood.

    --

    There's no reason for a sig here.

  76. Re:Since source is closed, we must wait for Apple. by znu · · Score: 1

    What the summary doesn't mention is that Apple has already whipped up a patch (took them two days) and it should be available to the public soon.

    --

    --
    This space unintentionally left unblank.
  77. Boycott John Copeland! by SPorter · · Score: 3

    John Copeland has 42 patents on things as obvious as "Functionally Static Type Semiconductor Shift Register with Half Dynamic-Half Static Stages" and "Magnetic Bubble Enhanced Propagation Pulse Write for Lateral Displacement Coding". I'm all for patents and all, but not for obvious ones like these. This is as bad as Amazon! I think we should boycott him!

  78. Re:Here's the info... by Anonymous Coward · · Score: 0

    I have read all of John Copeland's links carefully and the summary article referred to in this email and both are very well done. The negative comments about Copeland's research is totally unwarrented and ignorant! Obviouisly Apple is taking this very seriously, since they managed to post a fix during Christmas break, an unheard of speedy response! David Smith Founder/Publisher of MacTutor (now MacTech) magazine.

  79. Bug MUCH more than UDP by Burger+King · · Score: 1

    I noticed the ping problem awhile ago, and UDP is just the tip of the iceberg. A SYN (sent to any port, closed or not) will also prompt unpatched MacOS 9 to send the 1500 byte icmp packet. Stranger still, the OS will send the ping to all connected hosts every 17-22 minutes, but at no regular interval. The data in the packet is empty. However Apple managed to let something this apparent slip beyond alpa testing is beyond me.

  80. Macintoshes used for DOS? by Anonymous Coward · · Score: 0

    You Slashdot people are a bunch of mean and ignorant Macintosh haters. You just think we're stupid, but we're not. Mac users are just as smart and sometimes smarter than you Lunix übergeeks.

    Mac people have been able to do DOS for years now -- you can even run Windows with a Mac if you want. Of course, it's not like we'd want to. Lunix and DOS don't have pretty pictures, and doesn't that typing and all those little mouse buttons make your fingers sore? Windows 95 people say it's just as easy to use, but the graphics are better on a Mac.

    My dad says people who pick on Macintoshes are stupid assholes. I think I agree with him.

    1. Re:Macintoshes used for DOS? by Anonymous Coward · · Score: 0

      My mom says people who don't know DOS also stands for "Denial Of Service" are even dumber than those people who actually run DOS on a Mac.

      My uncle says Macs suck.

      My aunt divorced my uncle because he slept with a woman named Ivana who promised my uncle that she, Ivana, would do anything he, my uncle, wanted. He asked her for some kinky shit, lost his job a week later (he worked as a garbageman), and then found a note from Ivana saying that she preferred men with money and that she hitched a ride to Atlantic City.

      Ivana thanked him for the memories, said he was a real sicko for asking for all his kinky shit, and left him a silver box into which she put all the whips, high heels, and black frilly stuff that he'd bought for her.

      Last I heard (from my uncle) was that Ivana was working as a waitress at Harrah's in Atlantic City. She bought a Mac from Circuit City but now wishes she'd got an Athlon since she edits a lot of home movies on the Mac and thinks that its multimedia capabilities are pretty dismal. Ivana has seen the benchmarks and knows that AMD's give the best bang for the buck.

      She recently compiled a photo essay for my uncle in which she wears all kinds of new frilly stuff. She put it up on a web page (I forget the URL) and sent an e-mail to my uncle telling him about it.

      My uncle (god rest his soul) died not long after Ivana left him. He had a stroke and died while digging up the rhubarb patch in his garden. I have to tell Ivana this -- that he's dead and that she's a real bad person for leaving him like she did -- but I haven't gotten around to it.

      I've been too busy reading Slashdot, worrying about DeCSS, and composing letters to idiots who don't understand that DoS is not DOS.

  81. They already did sue, in fact. by hatless · · Score: 2

    OS9 did run on the TRS-80 Color Computer, though FYI, it was third-party. And the developers (or whoever owns it now) weren't pleased by APple swiping the name.

    See http://ww w.macobserver.com/news/99/september/990903/microwa relawsuit.html.

    1. Re:They already did sue, in fact. by Cramer · · Score: 1

      Being someone who owns OS-9/6809 and OS-9/68k (granted old as hell versions, but...), I can say it _is_ causing confusion. They lost on a technicallity... there's a perceived difference between a "Consumer OS" and an "RTOS". I used OS-9 as my "desktop" for 10 years! It's a great little OS.

      Personally, I think it stinks that Microware lost. They've had a trademark on "OS-9" for over 25 years. I personally know several of the people who wrote the original OS-9/6809.

  82. DOS Client? by stickyc · · Score: 2

    (sigh) I need to keep up with my TLA's. I spent 5 minutes trying to figure out why being able to emulate a PC command line interpreter using distributed clients on Mac OS9 was anything worth freaking out over.
    Sure, it's worth style points, but does CERT really need to know about it? :)

  83. Re:Can we get more information by miquels · · Score: 1

    Remeber, the bandwidth is used at the ethernet layer. A 29 byte udp packet still uses 1500 bytes of bandwidth.


    I've read this comment a few times now. It is nonsense, ofcourse. Ethernet packet are variably sized.

    --
    Living is a horizontal fall
  84. yup by crayz · · Score: 1

    As a Blue G3 owner, I was trying to get info out of Apple about the G4 ROM block, and they kept telling me they couldn't comment on rumors. Finally, when I had kept asking for a while(and they would delete my posts), they contacted my ISP and bitched about me.

    Those tech support guys are bastards, especially Todd. And no one else at Apple will comment on anything either.

    If you want more info about this, I'd just stay tuned to sites like:

    www.macnn.com
    www.xlr8yourmac.com
    www.maccentral.com/forum/
    www.macfixit.com
    www.macintouch.com

    Apple may keep its mouth shut until it has a fix. Apple might even wait for MacOS 9.0.1 to release a fix(see www.appleinsider.com)

    1. Re:yup by alfredo · · Score: 1

      There is such a climate of secrecy, it is amazing any info leaks out. Their secrecy is so frustrating, but understandable. If it is to work, it has to be company wide, and consistent.

      I am skipping OS9. I am willing to wait for OSX.

      --
      photosMy Photostream
  85. "OS-9"? by Cramer · · Score: 1

    Alright, I've seen enough of this... "OS-9" is an operating system designed by Microware in the early 80's. It's an extremely good, small, fast RTOS. It's also Microware's registered trademark -- hell, it's the product's name! It ticks me off to see people automatically associate "OS-9" as MacOS 9.

    I'm now taking bets on how long before Microware wakes up it's lawyers.

  86. Patch... to be applied before Jan 1 ?! by m.o · · Score: 2

    OK, this all seemed very strange, but I still had doubts that a mentally healthy professor of a respected university would spread hoax. But this was just too much. Quote:
    Apple has developed a patch, but it must be applied by OS-9 Macintosh owners before New Years Eve to be effective.

    I guess someone has somehow acquired access to this guy's webpage and put all the BS there (like Mahir :)

  87. Re:Can we get more information by miquels · · Score: 1

    Remeber, the bandwidth is used at the ethernet layer. A 29 byte udp packet still uses 1500 bytes of bandwidth.


    I've read this comment a few times now. It is nonsense, ofcourse. Ethernet packet are variably sized. And you can most certainly send a 29 byte UDP packet.

    --
    Living is a horizontal fall
  88. Re:Wouldn't that be quite difficult by Cramer · · Score: 2

    The minimum ethernet frame is 64bytes. The actual UDP packet contains 29 bytes of data. Those bytes then get a UDP + IP header attached to it -- that's usually about 40 bytes. The ethernet card (driver, whatever) adds the ethernet MAC header (14 bytes?) and puts it on the cable...

    Every layer the packet passes through with add and remove any necessary padding for transmission. For example, if that 69 byte IP frame were to pass through an ATM (AAL5) network, it would need two 53byte ATM cells.

  89. (OT) Test by Anonymous Coward · · Score: 0

    This is just a test on how much readers read this message ... PLEASE give a short reply if you have a threshold1 and actually read this one

    To the moderators: do NOT (i repeat: NOT) increase beyond 0 .. mark as offtopic if you want (it is :-)) but keep the score below 1 !!

    1. Re:(OT) Test by Anonymous Coward · · Score: 0

      i dont know what your saying, but i like the way your saying it

    2. Re:(OT) Test by enum · · Score: 0

      huh?

  90. Re:the Red Hat open source investment... by um...+Lucas · · Score: 1

    at least the microsoft poster was funny, being that it's slightly relevant to the topic... Microsoft did invest in apple... the joke is about the programmers...

    Redhat's done squat... so far as this discussion goes.

  91. Re:the Red Hat open source investment... by blue · · Score: 1
    The parent was funny, yours isn't. Why?

    • Microsoft invested in and partly owns Apple.
    • Redhat does not
  92. Re:Apple's Statement by waldoj · · Score: 2

    They've updated their statement:

    "Since CERT has posted their advisory this afternoon, it does appear to be something real. I still haven't been able to find any further internal information, but when I do, I will pass it along.

    John"

  93. Apple's Statement by waldoj · · Score: 5

    http://discuss.info.apple.com/boards/macos.nsf/424 f8fb007a848d1862564c60074f8f1/5B274CA6 954706958625685500635B28?OpenDocument

    "We have no official comment at this time.

    Remember, we have a policy of not discussing unannounced updates. Once I find out any further
    information, I will tell you what I can.

    For one thing, it smells like a hoax to me. First, there is already a product called "OT Tuner"
    from a third-party company (Sustainable Softworks), so we would be extremely unlikely to use
    this name. Second, we would never supply any kind of "patch" software to an outside party
    without making them sign a non-disclosure agreement. Third, most of the engineers were on
    holiday at the end of last week, and it is very unlikely a patch could have been developed and
    tested in such a short time without information going out internally within Apple (which hasn't
    happened).

    I'm not saying it is indeed a hoax, I'm just saying don't put a lot of validity to it until we know
    more.

    John Phelps
    Forum Leader - Apple Support Discussions"

  94. Wouldn't that be quite difficult by Asparfame · · Score: 3
    In order to perform a worthy DOS though, you would need to

    a) Have a very long list of Mac's running OS9

    b) Send out a lot of UPD packets

    In fact, you would have to send out as many packets as the attacked server will recieve. So basically, you have to have enough bandwidth to withstand your own DOS attack. Of course it does have the advantage of hiding your IP, but it sounds no more effective than "ping -f".

    --

    There's no reason for a sig here.

    1. Re:Wouldn't that be quite difficult by um...+Lucas · · Score: 2

      Forever now, i've operated under the assumption that frame size is variable... Which is why all those utilities are available (for win and mac) that allow you to change your MTU (is that the right term... and is it the right term for this discussion?) depending on the speed of your connection - small for modems high for ethernet...

      So, couldn't you send the packetr to the Macs using a very small frame size and have them in return clog the pipe for you? It sounds that way to me.... maybe i'm wrong

    2. Re:Wouldn't that be quite difficult by Cramer · · Score: 1

      This is an "MTU Path Discovery" exploit. When one machine wants to talk to another machine it's best to know how big a packet each can send without it being fragmented (broken into smaller packets to cross any given link.) The MTU for ethernet is 1500 -- you can set it lower if you want, but larger is good way to crash your machine. Not all router links in the world can handle a 1500 byte packet without fragmentation.

      SO, at the beginning of a connection, the computers at the endpoints attempt to determine the largest packet they can send without fragmentation. This is done by setting the "DF" (do not fragment) bit in the IP header. They then "listen" for ICMP messages indicating the packet would have to have been fragmented to get there. The packet would then be retransmitted with less data in it.

      This packet is usually generated by a router somewhere in between. It would appear there is a way to "trick" MacOS 9 into sending out a 1500byte packet to "do an MTU discovery". Personally, this sounds like a cut-n-dry ("oops") bug... 1500 byte ICMP packets would likely be dropped by any number of routers (see RFC1122 and RFC1812 for the rules governing ICMP messaging) AND, the report doesn't say anything about which ICMP message was being generated (there are 15 types of ICMP messages defined under Solaris 2.6 -- 13 under linux)

      Disclaimer: I've never used MacOS 9 nor have I seen any of it's network code. The above explaination is "in theory" only and does not necessarily indicate how any OS actually handles MTU path discovery.

    3. Re:Wouldn't that be quite difficult by Anonymous Coward · · Score: 0

      Well... The UDP packet could conceivable be a lot smaller than the 1500 bytes ICMP packet generated as a response...

    4. Re:Wouldn't that be quite difficult by Anonymous Coward · · Score: 0

      If its a discovery packet that gets sent wouldn't OS 9 be waiting for an ACKnowledgement packet? Maybe built into OS9 it sends 5 more packets along if it doesn't get a ACK withing 1 second? If this were the case (Which it may very well be not) then it would be a x5 factor of your available bandwith.

    5. Re:Wouldn't that be quite difficult by beme · · Score: 2

      Well, if it's not a hoax, the guy's site has some info pertaining to these questions.

      1) In his experiments, only macs running OS9 responded to the scans he ran. Easy way to gather a pretty big list.

      2) a 40 byte trigger packet results in a 1500 byte response, so you get a nifty little bandwidth multiplier there.

      The page to read is http://people.atl.mediaone .net/jacopeland/macattack.html


      -beme

      --

      -beme
      1971
  95. Can we get more information by mangino · · Score: 3

    Maybe I'm completely missing something, but can't you just send it an ICMP ping request with a forged source address and have it send the response? This doesn't sound like anything special. Maybe if we could get some more information about the type of ICMP packet that is sent this could be helpful.

    So normally, you send an ICMP response request packet (a ping packet) to a machine and it responds to you. This is a pretty simple concept. The problem is that you flood the connection with your ping requests. I believe ping floods are normally caused when you get the machine to respond on a broadcast or multicast address. If the mac just responds with a ping response, this isn't a very important discovery.

    However, there are other kinds of ICMP (Internet Control Message Protocol) packets. Maybe this isn't a straight ping request or ping response flood. Unfortunately, there isn't more information provided about it. Can someone post more information?
    --
    Mike Mangino Consultant, Analysts International

    --
    Mike Mangino
    mmangino@acm.org
    1. Re:Can we get more information by um...+Lucas · · Score: 2

      If any of these script kiddies has a web server somewhere that they can see the logs of, then it'd seem much easier to just see where the macs are coming from, and send the attack through them... if nothing else, it would add an extra step to finding who perpetrated the attack.

    2. Re:Can we get more information by Cramer · · Score: 1

      "A 29 byte udp packet still uses 1500 bytes of bandwidth."
      Please read some documents on ethernet before you say such things. This is 100% not true. "Frame"s are variable sized; "Cell"s are fixed sized.

      The MINIMUM size for an ethernet frame is 64bytes. The MAXIMUM size for an ethernet frame is somewhere over 1500bytes (1514 I think.) The number "1500" is the maximum MTU (Maximum Transmit Unit -- the largest amount of data to be place in a single packet) for the OSes networking layer -- it can be set lower.

      The OS generally handles the 64byte min. by padding the packet to 64bytes before handing it to the ethernet hardware. The lower limit is there to handle collision detection with maximum cable lengths. Basically, the transmitter needs to still be active when the signal reaches the end of the cable to be able to detect a collision. Of course, that only makes sense (to me at least) in the 10base-2 (coax) world where collisions are detected by the current placed on the wire.

      As for what goes on inside the cable modem network, your guess is about as good as mine. I would assume the technology is somewhat like ATM, but I have no idea. Anyone know how the cable modem works?

  96. Re:the Red Hat open source investment... by Anonymous Coward · · Score: 0

    apparently included in the RHAT open source investment, RHAT gave apple "some really good tcp/ip stack code".

    Looking forward to seeing this moderated up, just like its parent...

  97. Why just OS9 by Hard_Code · · Score: 2

    Is there something peculiar to OS9 that leaves it vulnerable to this attack? What about other OSs? Can they detect a spoof?

    Jazilla.org - the Java Mozilla

    --

    It's 10 PM. Do you know if you're un-American?
    1. Re:Why just OS9 by Pope · · Score: 2

      If it actually exists (see above remarks from Apple themselves), it's most likely a bug in Open Transport.
      Because OT is totally modular, any bug fix/patch would be a nice small download, well under a Meg, unless Apple decides to roll the patch into OS 9.0.1, coming soon.


      Pope

      --
      It doesn't mean much now, it's built for the future.
  98. Does this seem like a dumbass to anyone else? by CynicX32 · · Score: 3

    I mean, first the guy can't even properly spell OS 9 (there isn't a dash). Then he says that the attack can be easily perpetrated by people with root access to a large university system, as long as they can then erase all logs of their activity.

    Yup. Sounds easy as pie to me.

    Then there's some of his "proof", like the CERT email. From which he removes a paragraph with no indication what it used to say, and removes the PGP signature. It also merely talks about a completely different attack, and says "if we get time to look at this alleged OS 9 thing, we'll try."

    Just smells fishy to me.

    ryan

  99. trin00 / TFN is much more of a problem by Megane · · Score: 2

    This page presents evidence of a conspiracy to shut down Internet Connections. Zero-hour is probably New Years Eve, EST.

    And how exactly is this more dangerous than trin00 / Tribe Flood Network? For those who haven't heard of trin00/TFN, it is networks of hundreds of r0043d machines on the Internet, each running daemons with the sole purpose of flooding any IP from widely scattered machines, all under the control of 5kr1p4 k1dd3z.

    I suppose if the trin00/TFN code were updated to support this new kind of DoS as an option, it could be bad, but a bug like this can not be easily exploited to disrupt the internet itself, since Macs make up such a small population of the "live" Internet.

    This is not to say that the DoS can't be launched against the MacOS 9.0 machines themselves, but the potential for widespread 1/1/2000 mischief is limited.

    --
    #naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
  100. actually... by crayz · · Score: 1

    I'd mark both as funny, especially since the author said "j/k" at the end. Of course, most moderators... never mind, don't hurt me.

  101. Rescue on Fractalus by eGabriel · · Score: 1

    Yay! Now that OS9 is available on the Mac,
    I can run all of my old Color Computer III software. Now if I can just get a Mac with
    a 35 track single-sided floppy...

  102. Uh, dude? by Anonymous Coward · · Score: 0

    His whole page is about his Y2K Arabian DOS conspiracy theory, genius-boy. Maybe he should sell HIS story to Oliver Stone.

  103. P's a crock by Anonymous Coward · · Score: 0

    Master P's a punk ass. You must be too, wasting your time reciting an entire crappy rap with a few minor modifications. Here's a clue: Don't listen to pop 40 rap. Bustah.

  104. Whats the big deal? by enum · · Score: 1

    My home network is all g3's running OS9. Personally I have no desire to attack any DOS boxes. Does anyone actually use DOS anymore?

    1. Re:Whats the big deal? by _GNU_ · · Score: 1

      Oh, do I hope that was sarcastic.. if not.. ehm.. ack :)

    2. Re:Whats the big deal? by Anonymous Coward · · Score: 0

      enum, give me your i.p. so I can amplify a few packets in your direction, heh.

  105. Gonna go buy AAPL! by um...+Lucas · · Score: 1

    Their earning should skyrocket as all the little hackers/crackers rush to buy iMacs and/or OS 9 upgrades before Apple releases a fix... Years from now those babies will still be useful!

    Imagine tomorrow on News.com:

    Mac OS 9 deemed OS of choice for crackers... The rush is on to buy before 9.0.1 arrives!

  106. Re:the Red Hat open source investment... by Mr.+Flibble · · Score: 1

    Uhh, maybe I am mistaken, but the Linux TCP/IP stack is pretty damn good. The Windows TCP/IP stack has not changed since windows 95. (Read the documentation on nmap to see this: Phrack 54)

    I am uncertain about the stack in Win2k.

    So, how has Red Hat changed the TCP/IP stack in Linux? The post is only partially MS bashing, its pointing out a weakness in the Microsoft TCP/IP stack. I would ask that you clarify your post and explain how the Red Hat reference is relevant.

    Thanks.

    Only slightly on topic... :)

    --
    Try to hack my 31337 firewall!
  107. Since source is closed, we must wait for Apple... by Anonymous Coward · · Score: 0

    ...to bestow a solution upon us.

  108. CERT Advisory by ostiguy · · Score: 2

    CERT Advisory

    37.5x traffic amplication. Wheeeeeeee.

    Although that is incredibly dangerous, this guy is actually making a claim of an expected international y2k attack on the basis of two foreign port scans. hmmmm. Someone had a bit too much coffee.

    Anyhow, I can't seem to find any reference of this on Bugtraq. He appears to have only informed CERT and his local network admin.

    matt

  109. Apple Open Transport Tuner - Just released? by _GNU_ · · Score: 1

    Just up on versiontracker *HEH*

    Apple Open Transport Tuner - OS 9 & some 8.6 users for denial of service issues - 175k

    Apples servers seem very slashdotted of course...

  110. You're a troll in disguise.. by Anonymous Coward · · Score: 0

    Yeah, we really believe you're a Mac user. Probably some windoze luser impersonating a Mac luser...

  111. Apple just released OT Tuner 1.0 by blukens · · Score: 3

    Guess it's not a hoax, and I have to give props to Apple for the quick response...

    http://asu.info.apple.com/swupdates.nsf/artnum/n 11559

    Description
    OT Tuner 1.0 switches off an option in Open Transport that would cause a Macintosh to respond to certain small network packets with a large Internet Control Message Protocol (ICMP) packet. This update prevents Macintosh computers from being the cause of certain types of Denial of Service (DOS)
    issues.

    To install, drag the OT Tuner 1.0 file to the System Folder (the tuner will be put in the extensions folder for you). Then restart your Macintosh.

  112. uh, here's the fix for that 'hoax'... by Anonymous Coward · · Score: 0

    http://asu.info.apple.com/swupdates.nsf/artnum/n11 559

  113. Here's the info... by plaidhat · · Score: 3

    The Mac Resource Page had the best coverage of this DoS attack, imho. They cover it a lot better and in more detail than I could, so instead of repeating their words, I'll just post a link to them here: http://www.macresource.com/. Apple did indeed release a patch today by the name of "Open Transport Tuner". You can find it at the Apple Software Library (http://asu.info.apple.com/) on the "Recent Changes" page.

  114. Copeland by Sloppy · · Score: 4

    He's just jealous that they ended up not naming their OS after him.


    ---
    --
    As copyright owner of this comment, I authorize everyone to defeat any technological measure which limits access to it.
  115. No dumbass, read the article by Anonymous Coward · · Score: 0

    You only need to send a 29 byte packet to elicit a 1500 byte response.

  116. Wait... Doesn't OS9 run on Tandy CoCos? by Anonymous Coward · · Score: 0

    Radio Shack should sue. These are identical sames for an identical product (an OS).

  117. not just a Mac OS 9 problem by frankie · · Score: 5

    I defer to a recently-received email from Geoff Duncan, technical editor of Tidbits.com:

    *****

    Date: Tue, 28 Dec 1999 13:06:31 -0800
    From: Geoff Duncan
    Subject: Re: Mac DoS Attack

    While the attack outlined by Copeland is feasible, it's worth noting the 1500-byte ICMP responses he describes are not isolated to Mac OS 9, and are more-or-less standard practice in a number of networking implementations, regardless of whether those are based on Mentat's STREAMS. Macs running Mac OS 9 are by no means the only systems which demonstrate this behavior; in fact, I can easily make a number of dedicated routers behave the same way. If I were a cracker intent on causing damage with this sort of attack, why would I bother to locate Macintoshes on DSL or cable modem networks when I can utilize the same behaviors in thousands of routers all over the Internet, each of which is presumably easy to locate and has reasonable (or excessive) amounts of bandwidth at its disposal?

    The amplification attack Copeland describes involved gaining root access to a box with a big pipe - probably something running a flavor of Linux, Unix, or NT - and creating home-make forged packets. There are a number of potentially devastating attacks that can be launched under those circumstances that have nothing to do with Macs. TidBITS has been treated to a small selection of these sorts of attacks for the last several weeks. Calling for Mac OS 9 computers to be patched or taken off the net is not going to solve the problem or eliminate the feasibility of the attack Copeland describes.

    Also, Copeland's speculation that the datagrams he detected are probes pursuant to Macintosh-specific News Year's Eve attacks are best described as unsubstantiated speculation. At worst, they might be described as irresponsible. I would hope any further coverage this report gains in the Macintosh press will be more objective than what's currently playing on the standard "rumor" sites.

    *****

  118. Here's the gist of the scheme by seaportcasino · · Score: 2

    The purpose of this scheme, which I call a "Mac DoS Attack," is to generate a large amount of ICMP Internet traffic going to a specific target. This scheme can be replicated to attack many different targets, with little chance that the perpetrators will be caught. Phase I - Scanning The attackers run computer programs that sends UDP packets to every Internet address in the address ranges assigned to CATV cable modem and ADSL modem providers. Addresses that have Macintosh computers attached and operating will respond with a 1500-byte ICMP packet. These addresses are kept in a list for Phase 2. I will refer to the Macintosh computers at these addresses as "slaves."Phase 2 - Attack A computer at a location like a University is "root compromised." This means the aggressor group has used one of the many well-known techniques to gain the administrator password so they can load their own programs, which may be scheduled to run at a later time (like Christmas Eve or New Year's Eve). The compromised computer is given a list of addresses for 40 slaves, and the address of a specific target. The log files are erased so that no one will later be able to tell who installed the attack program. When the attack program starts running, it sends trigger packets in rotation to the forty or more slaves on its list. The source (return) Internet address is forged to be that of the target. The slaves then send a 1500 byte ICMP packet to the target each time they receive a 40-byte trigger packet. If the attack computer sends 4000 40-byte trigger packets per second (bit rate less than 1.3 Mbps), the slave will send 4000 1500-byte packets to the target (bit rate 48 Mbps). |-------------> Slave ------------>| Control |-------------> Slave ------------>| Computer ------->|-------------> Slave ------------>|-------> Target |-------------> Slave ------------>| | * * * | 4000 1500-byte 4000 40-B pkt/s 100 40-B pkt/s 100 1500-B pkt/s ICMP pkts/s to each slave from each slave = 48 Mbps This figure shows the process of "byte amplification." The target organization (or organizations) is cut off from the Internet because it's connection, a 1.5 Mbps (million bit per second) T-1 or a 45 Mbps DS-3 digital line is swamped with ICMP packets from forty different sources. Note that 30 different T-1 connections could be swamped by varying the return addresses in the trigger packets).

    Had to search the web site a little to find this, so I thought I'd post it to make people's lives easier. The problem I see with the theory above is that: what ADSL/Cable connection could support 48 Mbps of data from the Macs? I think there would have to be an AWFUL LOT of Mac slaves to actually swamp a DS-3 connection. In fact, I bet it isn't even possible.

  119. CERT Advisory CA-99-17 Denial-of-Service Tools by big-c · · Score: 1

    CA-99-17 Denial-of-Service Tools

    A new denial-of-service tool known as Tribe FloodNet 2K was released; a weakness in certain versions of MacOS allows intruders to use MacOS 9 as a "traffic amplifier."

  120. Re:DOS is bout it bout it by Garpenlov · · Score: 1

    Yes! First gangster rap, now ... script kiddie rap. It will bring the community together. Some will laugh at it, some will find it inspirational... Anyone that doesn't understand it can excluded.. Dodgin' beowulf clusters..

    --
    --- Where's my X.400 protocol decoder?