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High Severity BIND Vulnerability Advisory Issued
wiredmikey writes "The Internet Systems Consortium (ISC) and US-CERT have issued a high severity vulnerability warning, discovered by Neustar, which affects BIND, the most widely used DNS software on the Internet. Successful exploitation could enable attacker to cause Bind servers to stop processing all requests. According to the disclosure, 'When an authoritative server processes a successful IXFR transfer or a dynamic update, there is a small window of time during which the IXFR/update coupled with a query may cause a deadlock to occur. This deadlock will cause the server to stop processing all requests. A high query rate and/or a high update rate will increase the probability of this condition.'"
This sounds like a denial-of-service flaw. Such flaws are considered "low severity" in all but the rarest cases. A high-severity flaw would be one which either gives a hacker control of a service or access to sensitive information.
It depends entirely upon the requirements for availability. I agree that generally the A in the CIA triad is the least important, but not by any means always.
Imagine if this could be easily leveraged to shut down all DNS resolvers for, say, all of Comcast. Wouldn't you agree that it's probably a greater impact than, say, a single unimportant desktop somewhere in marketing being compromised by the Flash Of The Day vulnerability?
Thus is the black magic of IT risk management. :)
That said, my first thought when reading this headline was the same as yours.
Thanks, ISC, for patching a vulnerability a month after you found out about it and then telling us two weeks later that you did that
You know, I'm really tired of people who obviously don't write code saying crap like this. Fixing a subtle deadlock could quite realistically take a month. First, you need to figure out really why it happens. Then you need to figure out the CORRECT way to fix it, then you need to implement the fix, then you need to TEST the thing to make sure you didn't introduce anything ELSE that could cause a problem. If the bug was in an easy area of code, chances are it would have been found and fixed a long time ago. BIND has been around a long, long time. Anything left in there now is, by definition, hard to find and hard to fix.
Look folks, security bugs happen BECAUSE people whip out code without thinking and without testing. Now you ask for them to do exactly that? You need to get a grip on reality.