Multiple MIME-based content monitoring and antivirus products contain a flaw that may allow a malicious user to evade detection. This is due to the fact that many of these products do not properly implement RFC2231. Products which do implement the standard properly are able to use some of its oddities, such as permissive spacing, to cause vulnerable products to misinterpret the MIME header, and thus not properly detect the type and/or nature of the MIME attachment. This may result in a loss of integrity.
Classification
Location:
Remote/Network Access Required
Attack Type:
Input Manipulation
Impact:
Loss of Integrity
Exploit:
Exploit Available
Disclosure:
OSVDB Verified
Technical
Administrators should note that a large number of products use MIME filtering -- many of which are based on ripMIME -- and thus may be vulnerable as well.
Solution
For ripMIME, upgrade to version 1.4.0.0 or above. For all other products, check with the vendor to see if a patch, upgrade, or workaround is available, and if so apply it.