Adobe Reader allows users to view and print documents in Portable Document Format . This update fixes multiple vulnerabilities in Adobe Reader. These vulnerabilities are detailed on the Adobe security page APSB11-03, listed in the References section. A specially-crafted PDF file could cause Adobe Reader to crash or, potentially, execute arbitrary code as the user running Adobe Reader when opened. Multiple security flaws were found in Adobe reader. A specially-crafted PDF file could cause cross-site scripting attacks against the user running Adobe Reader when opened. All Adobe Reader users should install these updated packages. They contain Adobe Reader version 9.4.2, which is not vulnerable to these issues. All running instances of Adobe Reader must be restarted for the update to take effect.