Problem Description:
A security issue has recently been found and fixed in the Squid-2.X
releases up to and including 2.4.STABLE4.
Error and boundary conditions were not checked when handling
compressed DNS answer messages in the internal DNS code (lib/rfc1035.c).
A malicous DNS server could craft a DNS reply that causes Squid
to exit with a SIGSEGV.
The relevant code exists in Squid-2.3, Squid-2.4, Squid-2.5 and
Squid-2.6/Squid-HEAD, and is enabled by default.