Stack-based buffer overflow in the SSLv2 support in Mozilla Network Security Services (NSS) before 3.11.5, as used by Firefox before 1.5.0.10 and 2.x before 2.0.0.2, Thunderbird before 1.5.0.10, SeaMonkey before 1.0.8, and certain Sun Java System server products before 20070611, allows remote attackers to execute arbitrary code via invalid "Client Master Key" length values.