[Mimedefang] filter_bad_filename question

[James Ralston]

On 2003-07-29 at 14:05:34-0400 Mark London <mrl at psfc.mit.edu> wrote:

> This seemed to work fine, until I sent a web page from Netscape 7,
> and the receiver of the mail was told it had a bad attachment, the
> problem being that the attachment name was:
> 
> www.petfinder.com/pet.cgi?action=2&pet=1920982&adTarget=468
> petsgeneral&SessionID=3f26987d1a90052c-app2&display=&preview=1&row=0
> 
> I'm curious A) why no one else has reported this problem, and B)
> will my fix allow any bad attachments to get through?

For what it's worth...

We encountered this problem (and several similar problems).  A
significant number of otherwise legitimate messages (both incoming and
outgoing) were being flagged as invalid.

You might not have encountered it, but for some mail clients, if you
attach a message (that is, a message/rfc822 subpart) to a draft, the
name of the message/rfc822 part will be the contents of its Subject
header.  This can trigger the filename checks.

Our temporary solution was to disable the filename checks.  (We still
check for unwanted extensions, but the extension has to be an actual
extension (meaning, a suffix) in order to be flagged as invalid.)

-- 
James Ralston, Information Technology
Software Engineering Institute
Carnegie Mellon University, Pittsburgh, PA, USA