The remote host is missing an update to clamav announced via advisory DSA 1340-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201340-1

A NULL pointer dereference has been discovered in the RAR VM of Clam Antivirus (ClamAV) which allows user-assisted remote attackers to cause a denial of service via a specially crafted RAR archives. We are currently unable to provide fixed packages for the MIPS architectures. Those packages will be installed in the security archive when they become available. The old stable distribution (sarge) is not affected by this problem. For the stable distribution (etch) this problem has been fixed in version 0.90.1-3etch4. For the unstable distribution (sid) this problem has been fixed in version 0.91-1. We recommend that you upgrade your clamav packages.