Clam AntiVirus is a GPL anti-virus toolkit, designed for integration with mail servers to perform attachment scanning. Clam AntiVirus also provides a command line scanner and a tool for fetching updates of the virus database.
Clam AntiVirus is vulnerable to a buffer overflow in "libclamav/upx.c" when processing malformed UPX-packed executables. It can also be sent into an infinite loop in "libclamav/fsg.c" when processing specially-crafted FSG-packed executables.
By sending a specially-crafted file an attacker could execute arbitrary code with the permissions of the user running Clam AntiVirus, or cause a Denial of Service.
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-0.87"