[Mimedefang] exe in defective zip attachments gettingthrough mimedefang

Cliff Hayes chayes at afo.net
Thu Jan 14 13:14:47 EST 2010


Tried to send you 2 samples; got this error "550 5.1.1
<dmo at roaringpenguin.com>... User unknown"

I checked the valuse of ->read() per your request.  It is "3" which is
"format error in the zip file" which is what I expected.  Did some further
checking and here are the possible values:

AZ_OK (0) Everything is fine.
AZ_STREAM_END (1) The read stream (or central directory) ended normally.
AZ_ERROR (2) There was some generic kind of error.
AZ_FORMAT_ERROR (3) There is a format error in a ZIP file being read.
AZ_IO_ERROR (4) There was an IO error.

Based on the above, shouldn't you be allowing AZ_OK and AZ_STREAM_END?  Both
seem to be equivalent to OK.

I think I'll block 2, 3, and 4



-----Original Message-----
From: mimedefang-bounces at lists.roaringpenguin.com
[mailto:mimedefang-bounces at lists.roaringpenguin.com]On Behalf Of Dave
Sent: Thursday, January 14, 2010 11:10 AM
To: mimedefang at lists.roaringpenguin.com
Subject: Re: [Mimedefang] exe in defective zip attachments
gettingthrough mimedefang

On Thu, Jan 14, 2010 at 10:54:14AM -0600, Cliff Hayes wrote:
> if Archive::Zip doesn't return an AZ_OK then mimedefang lets the
> through.  From what I could find out, if Archive::Zip doesn't return AZ_OK
> then there is a problem with the zip file.  I'd rather block defective zip
> files then let them through.  In the code below, I substituted "return 0;"
> with "else { return 1; }" and that solved my problem.  Now good zips still
> go through, zips with exe's get replaced with warning, and defective
> I'm assuming) get replaced with warnings too.  I'm surprised that standard
> procedure is to let defective zips through.  Or am I understanding this
> wrong?

What value is ->read() returning?  It might be nice to check the status
value and determine if it's failing due to a corrupt zip file, or simply
due to a zip format that Archive::Zip doesn't recognize.

If you can grab a sample of the zip in question and send it to me
offlist, I'll take a look.

Dave O'Neill <dmo at roaringpenguin.com>    Roaring Penguin Software Inc.
+1 (613) 231-6599                        http://www.roaringpenguin.com/
For CanIt technical support, please mail: support at roaringpenguin.com
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