CVE 2011-2374
Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 3.6.18 and 4.x through 4.0.1, and Thunderbird before 3.1.11, 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.