imlib2 is an advanced replacement for image manipulation libraries such as libXpm. It is utilized by numerous programs, including gkrellm and several window managers, to display images.
Pavel Kankovsky discovered that several buffer overflows found in the libXpm library (see GLSA 200409-34) also apply to imlib (see GLSA 200412-03) and imlib2. He also fixed a number of other potential security vulnerabilities.
A remote attacker could entice a user to view a carefully-crafted image file, which would potentially lead to the execution of arbitrary code with the rights of the user viewing the image. This affects any program that utilizes of the imlib2 library.
There is no known workaround at this time.
All imlib2 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/imlib2-1.2.0"