The txXPathNodeUtils::getBaseURI function in the XSLT processor in Mozilla Firefox before 25.0, Firefox ESR 17.x before 17.0.10 and 24.x before 24.1, Thunderbird before 24.1, Thunderbird ESR 17.x before 17.0.10, and SeaMonkey before 2.22 does not properly initialize data, which allows remote attackers to execute arbitrary code or cause a denial of service (stack-based buffer overflow and application crash) via crafted documents.