The remote host is missing an update to squidguard announced via advisory DSA 2040-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202040-1

It was discovered that in squidguard, a URL redirector/filter/ACL plugin for squid, several problems in src/sgLog.c and src/sgDiv.c allow remote users to either: * cause a denial of service, by requesting long URLs containing many slashes this forces the daemon into emergency mode, where it does not process requests anymore. * bypass rules by requesting URLs whose length is close to predefined buffer limits, in this case 2048 for squidguard and 4096 or 8192 for squid (depending on its version). For the stable distribution (lenny), this problem has been fixed in version 1.2.0-8.4+lenny1. For the unstable distribution (sid), this problem has been fixed in version 1.2.0-9. We recommend that you upgrade your squidguard package.