PulseAudio is a sound system for POSIX OSes.
The pa_make_secure_dir function in core-util.c does not handle temporary files securely.
A local attacker could perform symlink attacks to overwrite arbitrary files with the privileges of the user running the application.
There is no known workaround at this time.
All PulseAudio users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-sound/pulseaudio-0.9.22"