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 score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) associated with each description below.
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.
- 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.
- 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.
NoteThe 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.
Users of Ghostscript are advised to upgrade to these updated packages, which contain backported patches to correct these issues.