Clam AntiVirus is an open source (GPL) anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail gateways.
A heap-based buffer overflow exists in the cli_scanpe function in libclamav/pe.c in ClamAV.
A remote attacker could possibly cause a Denial of Service condition via a specially crafted file.
There is no known workaround at this time.
All Clam AntiVirus users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-antivirus/clamav-0.98.5"