The remote host is missing an update to clamav announced via advisory DSA 1616-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201616-1

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. The Common Vulnerabilities and Exposures project identifies this weakness as CVE-2008-2713. For the stable distribution (etch), this problem has been fixed in version 0.90.1dfsg-3etch13. For the unstable distribution (sid), the problem has been fixed in version 0.93.1.dfsg-1.1. We recommend that you upgrade your clamav packages.