CVS (Concurrent Versions System) is an open-source network-transparent version control system. It contains both a client utility and a server.
A heap-based buffer overflow was discovered in the proxy_connect function in src/client.c in CVS.
An attacker, utilizing a remote HTTP proxy server, could cause a Denial of Service condition or possibly execute arbitrary code via a crafted HTTP response.
There is no known workaround at this time.
All CVS users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-vcs/cvs-1.12.12-r11"