CVE 2010-3173
The SSL implementation in Mozilla Firefox before 3.5.14 and 3.6.x before 3.6.11, Thunderbird before 3.0.9 and 3.1.x before 3.1.5, and SeaMonkey before 2.0.9 does not properly set the minimum key length for Diffie-Hellman Ephemeral (DHE) mode, which makes it easier for remote attackers to defeat cryptographic protection mechanisms via a brute-force attack.
See the 
CVE page on Mitre.org
for more details.
