Mozilla Firefox is an open source web browser. XULRunner provides the XULRuntime environment for Mozilla Firefox.A flaw was discovered in Mozilla Firefox that could be used to violate thesame-origin policy and inject web script into a non-privileged part of thebuilt-in PDF file viewer (PDF.js). An attacker could create a malicious webpage that, when viewed by a victim, could steal arbitrary files (includingprivate SSH keys, the /etc/passwd file, and other potentially sensitivefiles) from the system running Firefox. (CVE-2015-4495)Red Hat would like to thank the Mozilla project for reporting this issue.Upstream acknowledges Cody Crews as the original reporter.All Firefox users should upgrade to these updated packages, which containFirefox version 38.1.1 ESR, which corrects this issue. After installing theupdate, Firefox must be restarted for the changes to take effect.