LibAST is a utility library that was originally intended to accompany Eterm, but may be used by various other applications.
Michael Jennings discovered an exploitable buffer overflow in the configuration engine of LibAST.
The vulnerability can be exploited to gain escalated privileges if the application using LibAST is setuid/setgid and passes a specifically crafted filename to LibAST's configuration engine.
Identify all applications linking against LibAST and verify they are not setuid/setgid.
All users should upgrade to the latest version and run revdep-rebuild:
# emerge --sync # emerge --ask --oneshot --verbose ">=x11-libs/libast-0.7" # revdep-rebuild