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"DNS Forgery Pharming" Attack Against BIND 9
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.
Since when is a severe flaw in BIND's implementation news?
Proud member of the Weirdo-American community.
If you read the PDF, you will see that a good history of this kind of attack (and previous responses to it) are detailed. Apparently there has been is history of research into this kind of attack, with various counter measures. But the new attack (which seems like it would apply to almost all versions of BIND9 takes a different approach at "cracking" the PRNG which looks like it could be run against real-world servers.
I don't pretend to understand everything (or even most things) in the PDF, but it looks like solid research to me.
Prime numbers are exactly what Alan Greenspan says they are -S. Minsky
The TFA recommends using Trusteer's product to defeat this attack:
So, to recap. Vendor discovers a flaw and recommends their product.Film at 11:00.
It must have been something you assimilated. . . .
Bind was and is a mess. The patch is to use something else....
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
http://www.openbsd.org/advisories/res_random.txt http://cr.yp.to/djbdns/forgery-cost.txt
Frankly, yes. The basic concepts of a DNS server are fairly straightforward, but as demonstrated by this attack, the devil is in the details. This attack uses reasonably advanced cryptanalysis, and exploits the predictable behaviour of DNS clients. I suspect that this attack would also have been mitigated by the use of DNSSEC, but the roll-out of that has been held up for years - and DNSSEC itself introduces even more cryptographic complexity.
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!
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
Try looking at the copyright on djbdns. None, I repeat *none*, of Dan Bernstein's technically excellent solutions have propagated to broad use because of his extremely poor documentation, installation instructions, violations of the UNIX FileSystem Hierarchy, unwillingness to allow others to fork his code even for ease of packaging reasons, confusing licensing, etc.
r ez#djb. And like the absurd licensing conditions of Pine and the University of Washington wu-imapd, the refusal to accept input or insights from others or cooperate with its packaging for more stable configurations has led to their being discarded from most distributions.
The functionality of clever tools like QMail and djbdns and daemontools has thus wound up sidelined and ignored by mainline developers. There are numerous lengthy and well-frounded rants on this, such as http://linuxmafia.com/~rick/faq/index.php?page=wa
Why the hell is bind trying to implement its own random number generator? It's a piece of junk compared to the random numbers modern BSD OS's generate via libc.
-Matt
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