Netpbm is a toolkit for manipulation of graphic images, including conversion of images between a variety of different formats.
A stack-based buffer overflow exists in converter/ppm/xpmtoppm.c in Netpbm.
A remote attacker could entice a user to open a specially crafted XMP file using Netpbm, possibly resulting in execution of arbitrary code with the privileges of the process, or a Denial of Service condition.
There is no known workaround at this time.
All Netpbm users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/netpbm-10.49.00"
Packages which depend on this library may need to be recompiled. Tools such as revdep-rebuild may assist in identifying some of these packages.