proxytunnel -- format string vulnerability

A Gentoo Linux Security Advisory reports:

Florian Schilhabel of the Gentoo Linux Security Audit project found a format string vulnerability in Proxytunnel. When the program is started in daemon mode (-a [port]), it improperly logs invalid proxy answers to syslog.

A malicious remote server could send specially-crafted invalid answers to exploit the format string vulnerability, potentially allowing the execution of arbitrary code on the tunnelling host with the rights of the Proxytunnel process.

[source]