Kiax is a graphical softphone supporting the IAX protocol (Inter Asterisk eXchange), which allows PC users to make VoIP calls to Asterisk servers.
The iax_net_read function in the iaxclient library fails to properly handle IAX2 packets with truncated full frames or mini-frames. These frames are detected in a length check but processed anyway, leading to buffer overflows.
By sending a specially crafted IAX2 packet, an attacker could execute arbitrary code with the permissions of the user running Kiax.
There is no known workaround at this time.
All Kiax users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=net-misc/kiax-0.8.5_p1"