Vulnerability Issue in Implementations of the DNS Protocol



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A vulnerability affecting the Domain Name System (DNS)
protocol was identified by Dr. Steve Beaty from the
Department of Mathematical and Computer Science of
Metropolitan State College of Denver.

The Domain Name System (DNS) protocol is an Internet
service that translates domain names into Internet Protocol
(IP) addresses. Because domain names are alphabetic,
they're easier to remember, however the Internet is
really based on IP addresses; hence every time a domain
name is requested, a DNS service must translate the name
into the corresponding IP address.

The vulnerability concerns the recursion process used by
some DNS implementations to decompress compressed DNS
messages. Under certain circumstances, it is possible to
cause the DNS server to terminate abnormally.

All users of applications that support DNS are recommended
to take note of this advisory and carry out any remedial actions
suggested by their vendor(s).


- ferg

Seems to be similar to an issue discussed on Bugtraq in 1999 where they looked
to exploit the recursive nature of some DNS decompression implementations to
create a loop in the decompression code. At the time BIND wasn't vulnerable,
which doesn't stop client side code being vulnerable, but would have
mitigated the problem then.

Still we could do with some more details, although I guess enough detail to
start checking source code for the dedicated.

Hash: SHA1

Has anyone (a) experienced or noticed issues related to this
vulnerability (b) what action(s) have you taken to address this, if any?

What do folks at verisign and isc think about this?

Any insight will be appreciated.


Fergie (Paul Ferguson) wrote: