The remote host is missing an update to wwwoffle announced via advisory DSA 144-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20144-1

A problem with wwwoffle has been discovered. The web proxy didn't handle input data with negative Content-Length settings properly which causes the processing child to crash. It is at this time not obvious how this can lead to an exploitable vulnerability however, it's better to be safe than sorry, so here's an update. Additionally, in the woody version empty passwords will be treated as wrong when trying to authenticate. In the woody version we also replaced CanonicaliseHost() with the latest routine from 2.7d, offered by upstream. This stops bad IPv6 format IP addresses in URLs from causing problems (memory overwriting, potential exploits). This problem has been fixed in version 2.5c-10.4 for the old stable distribution (potato), in version 2.7a-1.2 for the current stable distribution (woody) and in version 2.7d-1 for the unstable distribution (sid). We recommend that you upgrade your wwwoffle packages.