libpng is a standard library used to process PNG (Portable Network Graphics) images. It is used by several programs, including web browsers and potentially server processes.
Two vulnerabilities have been discovered in libpng:
A context-dependent attacker could entice a user to open a specially crafted PNG file using an application linked against libpng, possibly resulting in execution of arbitrary code.
There is no known workaround at this time.
All libpng 1.6 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/libpng-1.6.16"
All libpng 1.5 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/libpng-1.5.21"