BugTraq
URI handling woes in Acrobat Reader, Netscape, Miranda, Skype Oct 05 2007 12:58PM
Juergen Schmidt (ju heisec de) (3 replies)
Re: URI handling woes in Acrobat Reader, Netscape, Miranda, Skype Oct 09 2007 11:03AM
Andreas Lindenblatt (azrael solution de)
Re: URI handling woes in Acrobat Reader, Netscape, Miranda, Skype Oct 09 2007 06:33AM
Andreas Lindenblatt (azrael solution de)
RE: URI handling woes in Acrobat Reader, Netscape, Miranda, Skype Oct 05 2007 07:54PM
Roger A. Grimes (roger banneretcs com) (1 replies)
[Disclosure: I work for Microsoft. But this is my opinion, not Microsoft's]

If I click on the test link in IE 7, by itself, it does not have the vulnerability.

The applications in question are accepting abitrary input and not validating correctly.

How is that a Microsoft or Windows problem?

Don't get me wrong, I want to protect end-users as much as the next person (as does MS), but if it is the application not validating correctly, could there not be hundreds of potential characters and strings that cause input validation problems in particular circumstances, which will vary according to the application?

If Microsoft scrubs out every potential malicious character, it's bound to break lots of legitimate applications. That would make plenty of users and developers mad.

At what point should Microsoft scrub URIs so that it hands off only "legitmate" characters "most of the time"? How could Microsoft determine ahead of time what is and isn't legitimate characters to pass to applications they don't own? If they block characters that affect certain applications, it might cause problems in other applications that have no problem with the character(s) in question?

What is the solution? The easy answer is to block the % character in this particular instance...but that's just a whack-a-mole fix.

I'm asking, with genuine interest and a listening ear, what is the best long term solution you envision, to solve the larger problem?

Roger

*****************************************************************
*Roger A. Grimes, InfoWorld, Security Columnist
*CPA, CISSP, CISA, MCSE: Security (2000/2003), CEH, yada...yada...
*email: roger_grimes (at) infoworld (dot) com [email concealed] or roger (at) banneretcs (dot) com [email concealed]
*Author of Windows Vista Security: Securing Vista Against Malicious Attacks (Wiley)
*http://www.amazon.com/Windows-Vista-Security-Securing-Malicious/dp/0470
101555
*****************************************************************

-----Original Message-----
From: Juergen Schmidt [mailto:ju (at) heisec (dot) de [email concealed]]
Sent: Friday, October 05, 2007 8:59 AM
To: bugtraq (at) securityfocus (dot) com [email concealed]; full-disclosure (at) lists.grok.org (dot) uk [email concealed]
Subject: URI handling woes in Acrobat Reader, Netscape, Miranda, Skype

Hello,

the URI handling problem on Windows XP systems with IE 7 installed hits a lot of applications, not only Firefox (and mIRC) -- namely Skype, Acrobat Reader, Miranda, Netscape.

To recap: with the installation of IE 7 Microsoft changes the handling of URLs that are passed to the operating system on Windows XP. After this, URLs that contain an invalid "%" encoding can launch abitrary programms. One example is:

mailto:test%../../../../windows/system32/calc.exe".cmd

that launches the calculator when activated in affected applications.
Firefox fixed this problem in 2.0.6. After being notified by heise Security, Skype fixed the problem in 3.5.0.239.

Still vulnerable (as of 4th of October) are:

Adobe Acrobat Reader 8.1: If a user clicks on such a link
in a PDF, calc.exe is executed.

Miranda v0.7: If a user klicks on this link in a chat window, calc.exe is
executed

Netscape 7.1: mailto is handled by Netscape itself, but
similar telnet:-links start the calculator.

This list can propably be extended with little effort.

On a question to MSRC if Microsoft is planning to react on this, we
recieved the following response:

"After its thorough investigation, Microsoft has revealed that this is
not a vulnerability in a Microsoft product." 

For further information see:

http://www.heise-security.co.uk/news/96982

bye, ju

--
Juergen Schmidt editor-in-chief heise Security www.heisec.de
Heise Zeitschriften Verlag, Helstorferstr. 7, D-30625 Hannover
Tel. +49 511 5352 300 FAX +49 511 5352 417 EMail ju (at) heisec (dot) de [email concealed]
GPG-Key: 0x38EA4970, 5D7B 476D 84D5 94FF E7C5 67BE F895 0A18 38EA 4970

[ reply ]
Re[2]: [Full-disclosure] URI handling woes in Acrobat Reader, Netscape, Miranda, Skype Oct 06 2007 04:13PM
Thierry Zoller (Thierry Zoller lu) (2 replies)
RE: Re[2]: [Full-disclosure] URI handling woes in Acrobat Reader, Netscape, Miranda, Skype Oct 07 2007 01:30AM
Roger A. Grimes (roger banneretcs com)
Re: [Full-disclosure] URI handling woes in Acrobat Reader, Netscape,Miranda, Skype Oct 06 2007 04:43PM
Geo. (geoincidents nls net) (3 replies)
Re: URI handling woes in Acrobat Reader, Netscape,Miranda, Skype Oct 11 2007 12:48PM
Thierry Zoller (Thierry Zoller lu)
Re[2]: [Full-disclosure] URI handling woes in Acrobat Reader, Netscape,Miranda, Skype Oct 06 2007 05:06PM
Thierry Zoller (Thierry Zoller lu) (3 replies)
Re: Re[2]: [Full-disclosure] URI handling woes in Acrobat Reader, Netscape,Miranda, Skype Oct 06 2007 06:52PM
Kurt Dillard (kurtdillard msn com) (1 replies)
Re: Re[2]: [Full-disclosure] URI handling woes in Acrobat Reader, Netscape,Miranda, Skype Oct 07 2007 01:40PM
Glynn Clements (glynn gclements plus com) (1 replies)
Re: [Full-disclosure] URI handling woes in Acrobat Reader, Netscape, Miranda, Skype Oct 08 2007 12:45AM
KJK::Hyperion (hackbunny s0ftpj org) (1 replies)


 

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