MIMEDefang in MIME-tools 5.414 allows remote attackers to bypass virus scanning capabilities via an e-mail attachment with a virus that contains an empty boundary string in the Content-Type header.
https://exchange.xforce.ibmcloud.com/vulnerabilities/17940
http://www.securityfocus.com/bid/11563
http://www.mandriva.com/security/advisories?name=MDKSA-2004:123
http://www.gentoo.org/security/en/glsa/glsa-200411-06.xml
http://lists.roaringpenguin.com/pipermail/mimedefang/2004-October/024959.html