Clam AntiVirus is "a multi-platform GPL anti-virus toolkit. ClamAV is often integrated into e-mail gateways and used to scan e-mail traffic for viruses. It supports virus scanning for a wide variety of packed Portable Executable (PE) binaries. WWPack is one of the supported packers". Remote exploitation of a heap overflow vulnerability in Clam AntiVirus' ClamAV, as included in various vendors' operating system distributions, allows attackers to execute arbitrary code with the privileges of the affected process.
http://www.securiteam.com/securitynews/5KP0C1PO0I.html
