The Common UNIX Printing System provides a portable printing layer for UNIX operating systems. A use-after-free flaw was found in the way CUPS handled references in its file descriptors-handling interface. A remote attacker could, in a specially-crafted way, query for the list of current print jobs for a specific printer, leading to a denial of service . Several cross-site scripting flaws were found in the way the CUPS web server interface processed HTML form content. If a remote attacker could trick a local user who is logged into the CUPS web interface into visiting a specially-crafted HTML page, the attacker could retrieve and potentially modify confidential CUPS administration data. Red Hat would like to thank Aaron Sigel of Apple Product Security for responsibly reporting the CVE-2009-2820 issue. Users of cups are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing the update, the cupsd daemon will be restarted automatically.