The bytecode engine in ClamAV before 0.97.3 allows remote attackers to cause a denial of service (crash) via vectors related to "recursion level" and (1) libclamav/bytecode.c and (2) libclamav/bytecode_api.c.
https://bugzilla.redhat.com/show_bug.cgi?id=746984
http://www.ubuntu.com/usn/USN-1258-1
http://www.securityfocus.com/bid/50183
http://www.openwall.com/lists/oss-security/2011/10/18/1
http://secunia.com/advisories/46826
http://secunia.com/advisories/46717
http://lists.fedoraproject.org/pipermail/package-announce/2011-November/068942.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-November/068941.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-November/068940.html