Red Hat Security Advisory 2015-0988-01 – Mozilla Firefox is an open source web browser. XULRunner provides the XUL Runtime environment for Mozilla Firefox. Several flaws were found in the processing of malformed web content. A web page containing malicious content could cause Firefox to crash or, potentially, execute arbitrary code with the privileges of the user running Firefox. A heap-based buffer overflow flaw was found in the way Firefox processed compressed XML data. An attacker could create specially crafted compressed XML content that, when processed by Firefox, could cause it to crash or execute arbitrary code with the privileges of the user running Firefox.