optipng -- arbitrary code execution via crafted BMP image

Secunia reports:

A vulnerability has been reported in OptiPNG, which
potentially can be exploited by malicious people to compromise
a user’s system.
The vulnerability is caused due to a boundary error in
the BMP reader and can be exploited to cause a buffer
overflow by tricking a user into processing a specially
crafted file.
Successful exploitation may allow execution of arbitrary
code.