zgv, xzgv: Heap overflow

Background

xzgv and zgv are picture viewing utilities with a thumbnail based file selector.

Description

Andrea Barisani of Gentoo Linux discovered xzgv and zgv allocate insufficient memory when rendering images with more than 3 output components, such as images using the YCCK or CMYK colour space. When xzgv or zgv attempt to render the image, data from the image overruns a heap allocated buffer.

Impact

An attacker may be able to construct a malicious image that executes arbitrary code with the permissions of the xzgv or zgv user when attempting to render the image.

Workaround

There is no known workaround at this time.

Resolution

All xzgv users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=media-gfx/xzgv-0.8-r2"

All zgv users should also upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=media-gfx/zgv-5.9"