squidGuard upstream has released patches fixing (quoting
from upstream advisories):
a, This patch fixes one buffer overflow problem in sgLog.c when overlong URLs
are requested. SquidGuard will then go into emergency mode were no blocking
occurs. This is not required in this situation.
b, This patch fixes two bypass problems with URLs which length is close to the
limit defined by MAX_BUF (default: 4096) in squidGuard and MAX_URL (default:
4096 in squid 2.x and 8192 in squid 3.x) in squid. For this kind of URLs the
proxy request exceeds MAX_BUF causing squidGuard to complain about not being
able to parse the squid request.
Upstream patches - squidGuard 1.4:
These issues affects the versions of the squidGuard package, as shipped
with Fedora release of 10 and 11.
squidGuard-1.4-8.fc10 has been submitted as an update for Fedora 10.
squidGuard-1.4-8.fc11 has been submitted as an update for Fedora 11.
Buffer overflow in sgLog.c in squidGuard 1.3 and 1.4 allows remote
attackers to cause a denial of service (application hang or loss of
blocking functionality) via a long URL with many / (slash) characters,
related to "emergency mode."
Multiple buffer overflows in squidGuard 1.4 allow remote attackers to
bypass intended URL blocking via a long URL, related to (1) the
relationship between a certain buffer size in squidGuard and a certain
buffer size in Squid and (2) a redirect URL that contains information
about the originally requested URL.
squidGuard-1.4-8.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report.
squidGuard-1.4-8.fc10 has been pushed to the Fedora 10 stable repository. If problems still persist, please make note of it in this bug report.