Updated firefox packages that fix several security issues are now availablefor Red Hat Enterprise Linux 5 and 6.The Red Hat Security Response Team has rated this update as having criticalsecurity impact. Common Vulnerability Scoring System base scores,which give detailed severity ratings, are available for each vulnerabilityfrom the CVE links in the References section. Mozilla Firefox is an open source web browser. XULRunner provides the XULRuntime environment for Mozilla Firefox.Several flaws were found in the processing of malformed web content. A webpage containing malicious content could cause Firefox to crash or,potentially, execute arbitrary code with the privileges of the user runningFirefox. A flaw was found in the way Chrome Object Wrappers were implemented.Malicious content could be used to cause Firefox to execute arbitrary codevia plug-ins installed in Firefox. A flaw in the way Firefox displayed URL values in the address bar couldallow a malicious site or user to perform a phishing attack.An information disclosure flaw was found in the way certain JavaScriptfunctions were implemented in Firefox. An attacker could use this flaw tobypass Address Space Layout Randomization and other securityrestrictions. For technical details regarding these flaws, refer to the Mozilla securityadvisories for Firefox 10.0.12 ESR. You can find a link to the Mozillaadvisories in the References section of this erratum.Red Hat would like to thank the Mozilla project for reporting these issues.Upstream acknowledges Atte Kettunen, Boris Zbarsky, pa_kt, regenrecht,Abhishek Arya, Christoph Diehl, Christian Holler, Mats Palmgren, ChiakiIshikawa, Mariusz Mlynski, Masato Kinugawa, and Jesse Ruderman as theoriginal reporters of these issues.All Firefox users should upgrade to these updated packages, which containFirefox version 10.0.12 ESR, which corrects these issues. After installingthe update, Firefox must be restarted for the changes to take effect.