Mozilla Firefox before 2.0.0.15 and SeaMonkey before 1.1.10 do not properly handle an invalid .properties file for an add-on, which allows remote attackers to read uninitialized memory, as demonstrated by use of ISO 8859 encoding instead of UTF-8 encoding in a French .properties file.

More... (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-2807)