libpng: Execution of arbitrary code
Gentoo Linux Security Advisory
||GLSA 200804-15 / libpng
||April 15, 2008
||April 15, 2008: 01
All supported architectures
A vulnerability in libpng may allow for execution of arbitrary code in
certain applications that handle untrusted images.
libpng is a free ANSI C library used to process and manipulate PNG
Tavis Ormandy of the Google Security Team discovered that libpng does
not handle zero-length unknown chunks in PNG files correctly, which
might lead to memory corruption in applications that call
png_set_read_user_chunk_fn() or png_set_keep_unknown_chunks().
A remote attacker could entice a user or automated system to process a
specially crafted PNG image in an application using libpng and possibly
execute arbitrary code with the privileges of the user running the
application. Note that processing of unknown chunks is disabled by
default in most PNG applications, but some such as ImageMagick are
There is no known workaround at this time.
All libpng users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/libpng-1.2.26-r1"