Integer overflow in the MathML component in Mozilla Firefox before 2.0.0.17 and 3.x before 3.0.2, Thunderbird before 2.0.0.17, and SeaMonkey before 1.1.12 allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via an mtd element with a large integer value in the rowspan attribute, related to the layout engine.

NOTE: Thunderbird shares the browser engine with Firefox and could be vulnerable if JavaScript were to be enabled in mail. This is not the default setting and we strongly discourage users from running JavaScript in mail. Without further investigation we cannot rule out the possibility that for some of these an attacker might be able to prepare memory for exploitation through some means other than JavaScript such as large images.