[Esd-l] Binary file problems in sanitizer

Peter Hanecak hanecak at megaloman.com
Fri Nov 29 00:11:01 PST 2002


On Thu, 28 Nov 2002, Thomas Nyman wrote:

> I'm running SuSE 8.0, with the Hardin sanitizer and spamassassin. Sanitizer 
> runs before spamassassin.
> I have the following problem. If I send a word document from my office to 
> my home adress - with the sanitizer off - I have no problems opening the 
> file. If I run sanitizer it defangs the word document as it should, however 
> it seems that the sanitizer not only defangs, i.e make a name change on the 
> document, but it also seems to change the mime type from binary to text 
> with the result that I cant open the word document even after I change the 
> "defanged-name". Can anyone explain why this is and if I can do something 
> about it? I simply want sanitizer to defang the document so you have to 
> make a filename change before opening it, but I dont want to corrupt the 
> file, which seems to be the case now. By the way, I'm using Mulberry on the 
> receiving end.

mime type for defanged documents has been changed from 
APPLICATION/OCTET-STREAM to TEXT/PLAIN to avoid magic scanning on Windows. 
This may lead to "corrupted" documents if MUA (mail user agent) performs 
some "filtering" or other changes to attachment assuming it is text (based 
on TEXT/PLAIN mime type).

So what you can do:

1) Force your MUA not to change/filter attachments.

2) Switch to other MUA.

3) Change John's sanitizer to use APPLICATION/OCTET-STREAM again instead 
of TEXT/PLAIN (and risk Windows performing magic scanning on attachments 
which may lead to running them even if they were defanged).



  Peter Hanecak <hanecak at megaloman.sk>
  GPG pub.key: http://www.megaloman.sk/gpg/hanecak.txt

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