Ghostscript is a set of software that provides a PostScript interpreter, a set of C procedures and an interpreter for Portable Document Format files. 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. Note: The fix for CVE-2010-4820 could possibly break existing configurations. To use the previous, vulnerable behavior, run Ghostscript with the "-P" option . 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.