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Security Experts Doubt SCO's Claims of DoS
devilkin writes "As a recent Slashdot story indicates, SCO claims their website was the target of a DoS (Denial of Service) attack. Was it really? The people at Groklaw think otherwise..."
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Wednesday, December 10 2003 @ 04:37 PM EST
SCO has reported that they are experiencing an attack on their servers. Groklaw has been flooded with information that indicates their story doesn't add up.
The consensus of what I am hearing is: That it is probably not an attack. That their description of the "attack" makes no sense. And that if what they are saying were true, SCO would be admitting to gross negligence.
First, I'm being told that Linux has a very simple preventative built in. Linux comes with the ability to block ALL SYN attacks. End of story. All major firewalls can do so also. They run their web site on Linux. CISCO routers can protect against SYN attacks too, I have been told, if properly enabled. Why does SCO persist in having such problems?
I knew one of Groklaw's readers is a security professional in Australia, so I wrote to him and asked if he'd take a look and give me his opinion.
Steve McInerney describes himself like this: "I worked for six years as the Technical Security member of the IT Security team for Australia's Department of Defense. Also I did IT Security policy writing/advice. More recently I was one of the senior designers/firewall/security experts at a company that manages Australia's largest federal government-certified Internet gateway." He just sent me his opinion:
"SCO has released a press release stating that their web site www.sco.com has come under a Distributed Denial of Service Attack (DDoS), specifically a SYN flood.
"Before we show how silly this statement is, let's explain SCO's position. A 'SYN Flood' attack is an attack that attempts to stop a server from accepting new connections. It's quite an old attack now, and has been relegated to the 'That was interesting' basket of attacks.
'A very simple analogy of a SYN attack: You have two hands, you are thus able to shake hands with at most two people at any one time. A third person who wants to shake your hand has to wait. Either you or one of the first two people can stop shaking hands so as to be able to accept the third person's handshake.
"In this instance SCO are claiming that 'thousands' are doing something similar to their web server. This is, in and of itself, plausible. Unfortunately if we look closer there are a few problems with this claim of SCO's.
"As stated above, the attack is quite an old one. Patches to all Operating Systems that I'm aware of, do exist to stop this sort of attack. For instance, a CISCO document: http://www.cisco.com/warp/public/707/4.html describes the attack and provides ways to stop it. Note the lines: 'Employ vendor software patches to detect and circumvent the problem (if available).' This means, quite simply, that patches exist to mitigate this attack.
Why hasn't SCO applied them?
Further SCO States:
"'The flood of traffic by these illegitimate requests caused the company's ISP's Internet bandwidth to be consumed so the Web site was inaccessible to any other legitimate Web user.'
"Interesting. If their bandwidth is consumed, then any servers nearby will also be inaccessible. That is www.sco.com has the IP address of 216.250.128.12 and ftp.sco.com has the IP address of 216.250.128.13 so the two servers are side by side, probably even on the same physical network hub/switch. Note that there is no room for a broadcast, etc., address - these servers are on the same subnet - i.e., on the same network device (hub/switch).
"Unfortunately for SCO, from Australia, ftp.sco.com is highly responsive. No bandwidth problems there that I can see - even though www.sco.com is still unavailable.
"The evidence then, is that their bandwidth is fine.
"So what about just the SYN flood? Well, even with patches, to successfully conduct a SYN flood you would tend to chew up available bandwidth anyway, which we aren't seeing. So I have quite strong doubts about the accuracy of this information.
"I feel quite
have you or any friends of yours taken part in SCO DDOS attack? If the overwhelming answer on Slashdot is no, then I guess we know the value of SCO's claims.
That's specious logic.
A single machine on cable or DSL can SYN flood a machine. The attacker sends a stream of SYN packets with forged source addresses, the victim machine replies back to the bogus IP and waits.. and waits.. and waits.. It takes negligible bandwidth to do this.
Trolling is a art,
Your thoughts would be correct. However, had you read the article, you would have noted that multiple COMPUTER SECURITY EXPERTS were consulted for feedback on the issue.
Silly grasshopper.
SCO Experiences Distributed Denial of Service Attack
It was suggested on the Yahoo BBS that perhaps this was a DNS IP transition that wasn't properly planned by the BOFH admin. Could that mean this website has been up and running all along on this new IP address?
SCO Grows Your Business http.://216.250.128.20 vs the old address of 216.250.128.13?
Inquiring minds want to know! News editors are breathless waiting! Investors are fretting! BSD users dread being blamed next! The SLTPD and FBI need your assistance in tracking down the real SCO-flaws
This past week the university that I work for has been the victim of an internal denial of service attack that may be related. From what I can gather, our sysadmins have traced the problem to some sort of irc virus/worm that is using student's computers to participate in a DDOS attack. The compromised computers were spoofing random ip adresses and (from what I heard) trying to hit SCO. These have all been stopped by our firewall, but they had been causing trouble with said firewall all week.
I don't have conformation that they were trying to hit SCO, but this headline jibes.
"When ideology and theology couple, their offspring are not always bad but they are always blind." -- Bill Moyers
Even more fishy: ftp.dev.caldera.com (216.250.128.14) was not mentioned in the post, but is on the same subnet as www and ftp.sco.com. Guess what? It's quite responsive at refusing anonymous logins. Plus, ftp.beta.caldera.com (.15), ftp.iso.caldera.com (.16) work just fine:That's a 0.9-second FTP session. Guess what else? Despite
Something doesn't add up.
they recompiled apache so it doesn't reveal the host OS
You don't have to recompile Apache to make it not reveal OS. ServerTokens (AFAIR) Directive is for setting this. Rather you need to recompile kernels to spoof TCP/IP fingerprints that are used to reveal OS running on host.
Her.
Groklaw is run by a chixx0r.
It's astonishing that rumors spread like wildfire if the facts are so easy to check.
If you monitor a few tens of thousands of unused IPv4 addresses, you can observe most DoS attacks involving randomly spoofed addresses. You just listen for backscatter ((sorry, no better resource appears to be available). These packets are created by the victim server when it tries to answer to requests that have been spoofed from your address space. Some people even keep statistics of that noise.
And guess what? Yesterday and today, there was plenty of backscatter from 216.250.128.12. Why was ftp.sco.com suddenly offline today? Well, beginning around 2003-12-11 10:49 UTC, you could observe backscatter from 216.250.128.13, too. Unless SCO is deliberately forging backscatter (and if they are, they are doing a pretty good job at it, it looks very much like the real thing), they were under attack, yesterday and today.