Damian Put discovered a vulnerability in the ClamAV anti-virus toolkit's parsing of Petite-packed Win32 executables. The weakness leads to an invalid memory access, and could enable an attacker to crash clamav by supplying a maliciously crafted Petite-compressed binary for scanning. In some configurations, such as when clamav is used in combination with mail servers, this could cause a system to fail open, facilitating a follow-on viral attack. A previous version of this advisory referenced packages that were built incorrectly and omitted the intended correction. This issue was fixed in packages referenced by the -2 revision of the advisory. The Common Vulnerabilities and Exposures project identifies this weakness as CVE-2008-2713 and CVE-2008-3215.