RHSA-2015:2594 - Security Advisory

Topic

Updated libpng packages that fix three security issues are now available
for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having Moderate security
impact. Common Vulnerability Scoring System (CVSS) base scores, which
give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

Description

The libpng packages contain a library of functions for creating and
manipulating PNG (Portable Network Graphics) image format files.

It was discovered that the png_get_PLTE() and png_set_PLTE() functions of
libpng did not correctly calculate the maximum palette sizes for bit depths
of less than 8. In case an application tried to use these functions in
combination with properly calculated palette sizes, this could lead to a
buffer overflow or out-of-bounds reads. An attacker could exploit this to
cause a crash or potentially execute arbitrary code by tricking an
unsuspecting user into processing a specially crafted PNG image. However,
the exact impact is dependent on the application using the library.
(CVE-2015-8126, CVE-2015-8472)

An array-indexing error was discovered in the png_convert_to_rfc1123()
function of libpng. An attacker could possibly use this flaw to cause an
out-of-bounds read by tricking an unsuspecting user into processing a
specially crafted PNG image. (CVE-2015-7981)

All libpng users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.7 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.7 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.7 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.7 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.7 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux EUS Compute Node 6.7 x86_64
• Red Hat Enterprise Linux for SAP Solutions for x86_64 - Extended Update Support 6.7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 1276416 - CVE-2015-7981 libpng: Out-of-bounds read in png_convert_to_rfc1123
• BZ - 1281756 - CVE-2015-8126 CVE-2015-8472 libpng: Buffer overflow vulnerabilities in png_get_PLTE/png_set_PLTE functions

CVEs

• CVE-2015-7981
• CVE-2015-8472
• CVE-2015-8126

References

• https://access.redhat.com/security/updates/classification/#moderate