clamav -- MS-Expand file handling DoS vulnerability

An iDEFENSE Security Advisory reports:

Remote exploitation of an input validation error in Clam
AntiVirus ClamAV allows attackers to cause a denial of
service condition.
The vulnerability specifically exists due to improper
behavior during exceptional conditions.
Successful exploitation allows attackers to exhaust file
descriptors pool and memory. Anti-virus detection
functionality will fail if there is no file descriptors
available with which to open files. Remote exploitation
can be achieved by sending a malicious file in an e-mail
message or during an HTTP session.