Re: NSFOCUS SA2001-07 : ActivePerl PerlIS.dll Remote Buffer Overflow Vulnerability

[<securityfocus.com.drew () overt org>]

Mailer: SecurityFocus
In-Reply-To: <20011116015506.17854.qmail () mail securityfocus com>

> From: Jim <raxor () dexlink com>
> Has anyone been able to duplicate this bug ? 

A *default* install of IIS5 (tested in w2k pro) with 
ActivePerl 5.6.1.629 is *not* vulnerable to this bug.  In 
order to become vulnerable, you must disable 
the "Check that file exists" option for PerlIS.dll.  (In 
order to do this, open up the IIS MMC, right click on a 
(virtual) directory in your web server, 
choose "Properties", click on the "Configuration..." 
button, highlight the ".plx" item, click "Edit", and then 
uncheck "Check that file exists".)

> Am I wrong or does the ISAPI version of ActivePerl 
> execute .plx files and not .pl as mentioned in the 
> advisory ? 

On my test machine (win2k pro), by default perl.exe 
handles .pl and perlIS.dll handles .plx

--
^Drew

http://guh.nu

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