RHSA-2012:0095

Problem Description:

Updated ghostscript packages that fix multiple security issues are now
available for Red Hat Enterprise Linux 5 and 6.

The Red Hat Security Response Team 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.

2. Relevant releases/architectures:

RHEL Desktop Workstation (v. 5 client) - i386, x86_64
Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64
Red Hat Enterprise Linux Desktop (v. 5 client) - i386, x86_64
Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64
Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64
Red Hat Enterprise Linux HPC Node (v. 6) - x86_64
Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64
Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64
Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64
Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64
Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. Description:

Ghostscript is a set of software that provides a PostScript interpreter, a
set of C procedures (the Ghostscript library, which implements the graphics
capabilities in the PostScript language) and an interpreter for Portable
Document Format (PDF) files.

An integer overflow flaw was found in Ghostscript's TrueType bytecode
interpreter. An attacker could create a specially-crafted PostScript or PDF
file that, when interpreted, could cause Ghostscript to crash or,
potentially, execute arbitrary code. (CVE-2009-3743)

It was found that Ghostscript always tried to read Ghostscript system
initialization files from the current working directory before checking
other directories, even if a search path that did not contain the current
working directory was specified with the "-I" option, or the "-P-" option
was used (to prevent the current working directory being searched first).
If a user ran Ghostscript in an attacker-controlled directory containing a
system initialization file, it could cause Ghostscript to execute arbitrary
PostScript code. (CVE-2010-2055)

Ghostscript included the current working directory in its library search
path by default. If a user ran Ghostscript without the "-P-" option in an
attacker-controlled directory containing a specially-crafted PostScript
library file, it could cause Ghostscript to execute arbitrary PostScript
code. With this update, Ghostscript no longer searches the current working
directory for library files by default. (CVE-2010-4820)

Note: The fix for CVE-2010-4820 could possibly break existing
configurations. To use the previous, vulnerable behavior, run Ghostscript
with the "-P" option (to always search the current working directory
first).

A flaw was found in the way Ghostscript interpreted PostScript Type 1 and
PostScript Type 2 font files. An attacker could create a specially-crafted
PostScript Type 1 or PostScript Type 2 font file that, when interpreted,
could cause Ghostscript to crash or, potentially, execute arbitrary code.
(CVE-2010-4054)

Users of Ghostscript are advised to upgrade to these updated packages,
which contain backported patches to correct these issues.

4. 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

5. Bugs fixed (http://bugzilla.redhat.com/):

599564 - CVE-2010-2055 ghostscript: gs_init.ps searched in current directory despite -P-
627902 - CVE-2009-3743 ghostscript: TrueType bytecode intepreter integer overflow or wraparound
646086 - CVE-2010-4054 ghostscript: glyph data access improper input validation
771853 - CVE-2010-4820 ghostscript: CWD included in the default library search path