Re: BAD NEWS: Microsoft Security Bulletin MS03-032

["Crist J. Clark" <cristjc () comcast net>]

On Tue, Sep 09, 2003 at 01:51:25PM -0700, Drew Copley wrote:
> > -----Original Message-----
> > From: Nathan Wallwork [mailto:owen () pungent org] 
> > Sent: Tuesday, September 09, 2003 1:18 PM
> >
> > On Mon, 8 Sep 2003, Drew Copley wrote:
> > > The only sure way to detect this, I already wrote about [to 
> > Bugtraq]. 
> > > That is by setting a firewall rule which blocks the 
> > dangerous mimetype 
> > > string
> > > [Content-Type: application/hta]. Everything else in the 
> > exploit can change. 
> >
> > Just so we are clear, the firewall wouldn't tbe he right 
> > place to catch 
> > this because that string could be split by packet 
> > fragmentation, so you'd 
> > need to look for it at an application level, after the data stream 
> > has been reassembled.  
>
> Yes, I mean "IPS rule" - "firewall rule" is a bit inaccurate- just a
> traditional term. Any IPS that does not handle fragmentation, though, has
> some serious problems. 

s/fragmentation/fragmentation and TCP reassembly/

You'd need both, and they are different things.
-- 
Crist J. Clark                     |     cjclark () alum mit edu
                                   |     cjclark () jhu edu
http://people.freebsd.org/~cjc/    |     cjc () freebsd org

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