CVE 2008-5016
The layout engine in Mozilla Firefox 3.x before 3.0.4, Thunderbird 2.x before 2.0.0.18, and SeaMonkey 1.x before 1.1.13 allows remote attackers to cause a denial of service (crash) via multiple vectors that trigger an assertion failure or other consequences.
See the 
CVE page on Mitre.org
for more details.
