CVE 2011-3648
Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 3.6.24 and 4.x through 7.0 and Thunderbird before 3.1.6 and 5.0 through 7.0 allows remote attackers to inject arbitrary web script or HTML via crafted text with Shift JIS encoding.
See the
CVE page on Mitre.org
for more details.