From MFSA 2008-12:
Security research firm iDefense reported that researcher regenrecht discovered a
heap-based buffer overflow vulnerability in Mozilla mail code which could
potentially allow an attacker to run arbitrary code. The vulnerability is caused
by allocating a buffer that can be three bytes too small in certain cases when
viewing an email message with an external MIME body.
Users can prevent the vulnerable code from being triggered by setting the
"mailnews.display.disallow_mime_handlers" property to any value greater than or
equal to 3.
This issue was already addressed in Thunderbird and SeaMonkey packages shipped
in Red Hat Enterprise Linux via following advisories:
thunderbird-22.214.171.124-1.fc8 has been pushed to the Fedora 8 stable repository. If problems still persist, please make note of it in this bug report.
thunderbird-126.96.36.199-1.fc7 has been pushed to the Fedora 7 stable repository. If problems still persist, please make note of it in this bug report.
This issue was addressed in:
Red Hat Enterprise Linux: