3proxy is a multi-protocol proxy, including HTTP/HTTPS/FTP and SOCKS support.
The 3proxy development team reported a buffer overflow in the logurl() function when processing overly long requests.
A remote attacker could send a specially crafted transparent request to the proxy, resulting in the execution of arbitrary code with privileges of the user running 3proxy.
There is no known workaround at this time.
All 3proxy users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-proxy/3proxy-0.5.3h"