RHSA-2012:0302 - Security Advisory

Topic

Updated cups packages that fix one security issue and various bugs are now
available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

The Common UNIX Printing System (CUPS) provides a portable printing layer
for Linux, UNIX, and similar operating systems.

A heap-based buffer overflow flaw was found in the Lempel-Ziv-Welch (LZW)
decompression algorithm implementation used by the CUPS GIF image format
reader. An attacker could create a malicious GIF image file that, when
printed, could possibly cause CUPS to crash or, potentially, execute
arbitrary code with the privileges of the "lp" user. (CVE-2011-2896)

This update also fixes the following bugs:

• Prior to this update, the "Show Completed Jobs," "Show All Jobs," and

"Show Active Jobs" buttons returned results globally across all printers
and not the results for the specified printer. With this update, jobs from
only the selected printer are shown. (BZ#625900)

• Prior to this update, the code of the serial backend contained a wrong

condition. As a consequence, print jobs on the raw print queue could not be
canceled. This update modifies the condition in the serial backend code.
Now, the user can cancel these print jobs. (BZ#625955)

• Prior to this update, the textonly filter did not work if used as a pipe,

for example when the command line did not specify the filename and the
number of copies was always 1. This update modifies the condition in the
textonly filter. Now, the data are sent to the printer regardless of the
number of copies specified. (BZ#660518)

• Prior to this update, the file descriptor count increased until it ran

out of resources when the cups daemon was running with enabled
Security-Enhanced Linux (SELinux) features. With this update, all resources
are allocated only once. (BZ#668009)

• Prior to this update, CUPS incorrectly handled the en_US.ASCII value for

the LANG environment variable. As a consequence, the lpadmin, lpstat, and
lpinfo binaries failed to write to standard output if using LANG with the
value. This update fixes the handling of the en_US.ASCII value and the
binaries now write to standard output properly. (BZ#759081)

All users of cups are advised to upgrade to these updated packages, which
contain backported patches to resolve these issues. After installing this
update, the cupsd daemon will be restarted automatically.

Solution

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

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 625900 - STR #3436: Jobs buttons not working correctly when viewing a specific printer
• BZ - 625955 - Serial back end has inverted SIGTERM block
• BZ - 660518 - textonly filter won't work as a pipe with copies=1
• BZ - 668009 - avc calls leak file descriptors
• BZ - 727800 - CVE-2011-2896 David Koblas' GIF decoder LZW decoder buffer overflow

CVEs

• CVE-2011-2896

References

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