CVE 2012-3971
Summer Institute of Linguistics (SIL) Graphite 2, as used in Mozilla Firefox before 15.0, Thunderbird before 15.0, and SeaMonkey before 2.12, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via vectors related to the (1) Silf::readClassMap and (2) Pass::readPass functions.
See the 
CVE page on Mitre.org
for more details.
