Re: Apache Illegal Request Handling Possible XSS Vulnerability

[Kradorex Xeron <admin () digibase ca>]

That would severely cut most extensibility and require further implementations 
to be hardcoded, thus limiting apache's modular nature.

The original RFC would be insufficient for it's list as there are modules such 
as webdav (as in the previous example) that add to that list of methods

Apache isn't just your basic run-of-the-mill "GET/POST" HTTPD, it is highly 
extensible, sure, if it WAS a basic one, I could see limiting that list, but 
it's quite advanced and modular in design.

On Tuesday 24 April 2007 05:18, Michal Majchrowicz wrote:
> Hi.
> I think that server should have a list of valid requests. In fact
> Apache warns you sometimes that valid requests are:
> "GET/POST/TRACE/OPTIONS". The solution that it just accepts everything
> as request and protocol makes no sense. What kind of protocol is
> "<script>"?
> Regards Michal.
>
> On 4/24/07, Richard Moore <rich () westpoint ltd uk> wrote:
> > Michal Majchrowicz wrote:
> > > Hi.
> > > I think now we can classify this as flaw in Apache. It accepts
> > > requests that simply make no sense. Take a look at this example:
> > > <script>alert(document.cookie);</script> /test.php
> > > <script>alert(document.cookie);</script>
> > > In some circumstances it may cause XSS vulnerability:
> > > <?php
> > >         echo $_SERVER['REQUEST_METHOD'];
> > >         echo $_SERVER['SERVER_PROTOCOL'];
> > > ?>
> >
> > As Kradorex Xeron said, that's a flaw in the script. Apache needs
> > to let arbitrary verbs through to the PHP (or other server extension)
> > otherwise tools like webdav that require additional verbs could not
> > be implemented. It is possibly arguable that it should restrict the
> > verbs to a single alphanumeric string, but it certainly can't be
> > counted on to be just GET/POST etc.
> >
> > Cheers
> >
> > Rich.
> >
> > > I am now investigating other possible attacks.
> > > Regards Michal Majchrowicz.
> > >
> > > _______________________________________________
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> > --
> > Richard Moore, Principal Software Engineer,
> > Westpoint Ltd,
> > Albion Wharf, 19 Albion Street, Manchester, M1 5LN, England
> > Tel: +44 161 237 1028
> > Fax: +44 161 237 1031
>
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