CVE 2013-0801
Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 21.0, Firefox ESR 17.x before 17.0.6, Thunderbird before 17.0.6, and Thunderbird ESR 17.x before 17.0.6 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors.
See the 
CVE page on Mitre.org
for more details.
