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"DNS Forgery Pharming" Attack Against BIND 9

Posted by kdawson on from the better-hope-sitekey-works dept.

Monley writes "Help Net Security is running a story about a severe flaw in BIND's implementation that allows fraudsters to efficiently predict generated random numbers without the need to control the route between the user and the DNS server. (Here are HTML and PDF versions of the paper.) Using this vulnerability, fraudsters can remotely forge DNS responses and direct users to fraudulent websites, which can steal the user's sign-in credentials and do other mischief. The flaw was discovered by security researcher and Trusteer's CTO, Amit Klein." The ISC has released a patch to BIND 9.

15 of 105 comments (clear)

  1. New by HomelessInLaJolla · · Score: 1, Insightful

    However, security researcher and Trusteer's CTO, Amit Klein, has discovered a severe flaw in BIND's implementation which allows fraudsters to efficiently predict generated random numbers without the need to control the route between the user and the DNS server. How long has BIND been using the same random number generator? I'm a little bit skeptical that Mr. Klein is the first person to consider the possibility of mimicking its behavior.

    Maybe the headline should read,"Exploit which bored college students figured out fifteen years ago is finally released to the mainstream".
    --
    the NPG electrode was replaced with carbon blac
    1. Re:New by dave562 · · Score: 2, Insightful

      Maybe those bored college students should have gotten off their asses, put down the bongs and published some research that they would have been paid for.

    2. Re:New by hal9000(jr) · · Score: 3, Insightful

      Maybe those bored college students should have gotten off their asses, put down the bongs and and written some bots that they would have been paid for.

      Oh wait, that isn't ethical ...

  2. Come again? by Angst+Badger · · Score: 4, Insightful

    Since when is a severe flaw in BIND's implementation news?

    --
    Proud member of the Weirdo-American community.
  3. Our product not vulnerable to flaw we discovered.. by fahrbot-bot · · Score: 3, Insightful
    The flaw was discovered by security researcher and Trusteer's CTO, Amit Klein.

    The TFA recommends using Trusteer's product to defeat this attack:

    Mutual authentication solutions, such as Trusteer's Rapport, which strongly authenticates the destination website and prevents access to unauthenticated websites, can defeat the attack.
    So, to recap. Vendor discovers a flaw and recommends their product.
    Film at 11:00.
    --
    It must have been something you assimilated. . . .
  4. Re:Troll? Y'all are NEWBS! by TheRaven64 · · Score: 2, Insightful

    Consider this: BIND is the only server that I've ever seen a distro package so as to be easily chrooted. Why do you suppose that is?

    Because BIND is the only one that's easy to run in a chroot. OpenBSD also runs Apache in a chroot, but it means you lose features, like the ability to share everyone's ~/public_html. BIND is quite rare among servers in that it's non-trivial but has fairly meagre requirements when it comes to disk access. I can't think of any others off the top of my head that meet this requirement, with the exception of an ftpd that is only used for anonymous FTP, and these tend to support chroot too now.
    --
    I am TheRaven on Soylent News
  5. Don't Diss Bind by toonerh · · Score: 3, Insightful

    Bind has been around since the dawn of Vint Cerf's IP, but it has been redesigned and rewritten several times. The RFC that says replies go via UDP make it a security risk, but also make the net work better.

    In 2007, where 1000,s of "researchers" spend their lives trying to break the Internet.... This stuff happens. BIND, SendMail and classic solutions are attacked. Amazingly they hold up better than Windows!

    1. Re:Don't Diss Bind by Anonymous Coward · · Score: 2, Insightful

      Yeah, better than Windows.

      Since this is Slashdot the parent post will be modded up and I'll be modded down, but the truth of the matter is that the DNS server that ships with Windows has never has a single vulnerability.

      Wow, you must have a VERY short memory. Try thinking back to just earlier this year, when Microsoft Security Advisory (935964) came out. And that is just one of MANY flaws over the years in MS DNS server! Hell, their DNS server for NT4 and earlier releases of Win2K (pre SP3) ran so sloppy that most people had to write scripts to stop/restart their MS DNS servers nightly! I should know, I was one of them. It was the only way to fix memory leaking problems that would lead to cache lookup failures. And lets not forget the long era of MS DNS cache poisoning...

      No, BIND has proven it self to be MUCH more reliable for serious Internet servers than MS DNS. Just like Unix/Linux has proven to be a better OS for serious Internet servers than MS Windows. There is a reason the REAL Internet servers of the world use Unix/Linux and BIND. It's because they handle more critical traffic than any thing else, they absolutely have to work, and MS products are NOT up to that task! No amount of marketing hype can counter the real world expeirence of professional network engineers, and the pro's choose Unix. Windows Server has become more reliable over the years, and is viable product for small and medium businesses. But it has never been, currently isn't, and may never be reliable enough for those really critical high end servers that large ISPs, governments, and businesses need.

      The only reason people like you bitch about the popularity of Unix/Linux for high end servers is because you obviously know little about such things, but want to pretend that because you can install Windows 2003 Server and Exchange that you now know something about network engineering. Sorry, you don't... No one who does would have said "the DNS server that ships with Windows has never has a single vulnerability" because they would have had the real world expeirence of dealing with the problems that DO EXIST with that product! Knowing your way around a Windows server does make you talented, but it doesn't put you in a position where you know enough to go around dissing technologies you have obviously never even used...

  6. Re:Yes but... by matthewmok · · Score: 2, Insightful

    Moron,

    It is related to MS DNS -- a SYSTEM you said did not have any vulnerabilities.

    It's not hard to get a connection and a rooted machine in somebody's internal network. Also -- I can't think of anybody that would use MS DNS server outside on the Internet. If you do then that confirms my opinion of you.

  7. Re:FOSSie fix!!! by m.dillon · · Score: 3, Insightful

    A large number of programmers can make minor modifications to small software applications.

    A medium number of programmers can make minor modifications to medium-sized software applications.

    Very few programmers can make any sort of modification to very large software applications. Very, very few.

    Bind is a very large, complex piece of software. A good portion of that complexity is due to poor documentation and badly designed algorithms (a problem I've had with bind from the first release on through today), but at this point the majority of the complexity is due to feature creep. I still use bind simply because I do not have the desire to write a replacement for it, and because the only other really good DNS package has a copyright and licence on it that makes it virtually unusable. Software gets stale as it gets older... if I can't keep software up to date after the original author has lost interest then I have no interest incorporating said software, no matter how good it is.

    -Matt

  8. Re:Troll? Y'all are NEWBS! by Wdomburg · · Score: 2, Insightful

    Eh? BIND9 has a relatively tame history in terms of vulnerabilities. Just using the updates to RHEL3 as a quick and dirty metric, there have been two security updates compared to 5 openssh, 6 openssl, 11 php, 12 apache, 20 kernels, etc.

    Unfortunately a lot of people seem stuck in the past and still judge BIND from the 4.x and 8.x days.

  9. So.. if BIND9 sucks.. what is an alternative? by wethion · · Score: 2, Insightful

    Lets see, it has to be GPLed or BSDed, run on every platform, be insanely robust, free as in beer, tested so thoroughly that it ought to make the law of gravity look like shaky science. So, based on those criteria, what DNS software could hold up? Just wondering. Peace, V

    --
    Jon Postel, R.I.P. You are missed.
    1. Re:So.. if BIND9 sucks.. what is an alternative? by Just+Some+Guy · · Score: 2, Insightful

      Well, one answer: djbdns

      djbdns is proprietary, source-available software. It's nowhere near BSD or GPL licensed.

      --
      Dewey, what part of this looks like authorities should be involved?
  10. Re:Jeezus freaking A Christ by eggnet · · Score: 4, Insightful

    Probably because BIND has to be cross-platform. I'm sorry to break this to you Matt, but some people use inferior operating systems without good random number generation function. That doesn't prevent BIND from using superior OS provided services for platforms that do have good random number generators. They decided not to do it, plain and simple.
  11. Re:Complexity breeds problems. by Anonymous Coward · · Score: 1, Insightful

    Yes, universal deployment of DNSSEC would have completely defeated this attack.