libpng: Information disclosure

Background

libpng is the official PNG reference library used to read, write and manipulate PNG images.

Description

Jeff Phillips discovered that libpng does not properly parse 1-bit interlaced images with width values that are not divisible by 8, which causes libpng to include uninitialized bits in certain rows of a PNG file.

Impact

A remote attacker might entice a user to open a specially crafted PNG file, possibly resulting in the disclosure of sensitive memory portions.

Workaround

There is no known workaround at this time.

Resolution

All libpng users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=media-libs/libpng-1.2.37"