PHPShell 2.4 Session Fixation

`[+] Credits: John Page AKA hyp3rlinx  
[+] Website: hyp3rlinx.altervista.org  
[+] Source:  
http://hyp3rlinx.altervista.org/advisories/PHPSHELL-v2.4-SESSION-FIXATION.txt  
[+] ISR: ApparitionSec  
  
  
  
Vendor:  
==================================  
sourceforge.net/projects/phpshell/  
phpshell.sourceforge.net/  
  
  
  
Product:  
==============  
PHPShell v2.4  
  
  
  
Vulnerability Type:  
===================  
Session Fixation  
  
  
  
CVE Reference:  
==============  
N/A  
  
  
  
Security Issue:  
================  
PHPShell does not regenerate the Session ID upon authentication, this can  
potentially allow remote attackers to access parts of the application  
using only a valid PHPSESSID if PHP.INI setting for  
session.use_only_cookies=0.  
  
Since an existing XSS vulnerability exists in PHPShell "  
http://hyp3rlinx.altervista.org/advisories/PHPSHELL-v2.4-CROSS-SITE-SCRIPTING.txt"  
the risk is  
increased if an authenticated user clicks an attacker supplied link and the  
attacker finds way to access or set the victims Cookie.  
  
In 'phpshell.php' line 153 we see call to PHP function session_start();  
  
After user authentication no call to "session_regenerate_id()" is made  
leaving the authenticated session id same as pre-auth session id.  
However, "session.use_only_cookies=1" is default since PHP 4.3.0, so to  
exploit it would require that PHP.INI is set to session.use_only_cookies=0  
on the victims system.  
  
When accessing the application using the session fixation flaw and  
attempting to run system command the application luckily redirects to login  
form.  
However, if a victim is actively changing directorys, reading files etc...  
attackers may still be able to read current directory and files open  
in the victims PHPShell console window.  
  
  
  
Exploit/POC:  
=============  
  
1) Login to PHPShell run commands to CD to Windows directory and run DIR  
command etc, then find and copy the PHPSESSID Cookie  
  
2) Open a second browser (InternetExplorer) and access the application  
cleanly for first time using the PHPSESSID in URL.  
  
e.g.  
  
http://VICTIM-IP/phpshell-2.4/phpshell.php?PHPSESSID=<STOLEN-SESSION-ID>  
  
You should see what the authenticated victim now sees...  
  
e.g.  
  
Current Working Directory:  
Change to subdirectory:  
  
07/13/2009 08:51 PM 24,576 Microsoft.MediaCenter.iTv.Hosting.dll  
11/20/2010 10:24 PM 147,968 Microsoft.MediaCenter.iTV.Media.dll  
07/13/2009 08:52 PM 45,056 Microsoft.MediaCenter.ITVVM.dll  
11/20/2010 10:24 PM 56,320 Microsoft.MediaCenter.Mheg.dll  
11/20/2010 10:24 PM 114,688 Microsoft.MediaCenter.Playback.dll  
11/20/2010 10:24 PM 1,572,864 Microsoft.MediaCenter.Shell.dll  
11/20/2010 10:24 PM 241,664 Microsoft.MediaCenter.Sports.dll  
11/20/2010 10:24 PM 327,168  
Microsoft.MediaCenter.TV.Tuners.Interop.dll  
11/20/2010 10:24 PM 2,596,864 Microsoft.MediaCenter.UI.dll  
10/29/2011 12:23 AM 465,920 mstvcapn.dll  
11/20/2010 10:24 PM 88,576 NetBridge.dll  
07/13/2009 08:51 PM 106,496 RegisterMCEApp.exe  
06/10/2009 04:04 PM 129,528 segmcr.ttf  
  
etc...  
  
  
  
Network Access:  
===============  
Remote  
  
  
  
  
Severity:  
=========  
Medium  
  
  
  
Disclosure Timeline:  
=============================  
Vendor Notification: No reply  
Also, the INSTALL file "Bugs? Comments? Tracker System link" is HTTP 404  
http://sourceforge.net/tracker/?group_id=156638  
February 18, 2017 : Public Disclosure  
  
  
  
[+] Disclaimer  
The information contained within this advisory is supplied "as-is" with no  
warranties or guarantees of fitness of use or otherwise.  
Permission is hereby granted for the redistribution of this advisory,  
provided that it is not altered except by reformatting it, and  
that due credit is given. Permission is explicitly given for insertion in  
vulnerability databases and similar, provided that due credit  
is given to the author. The author is not responsible for any misuse of the  
information contained herein and accepts no responsibility  
for any damage caused by the use or misuse of this information. The author  
prohibits any malicious use of security related information  
or exploits by the author or elsewhere. All content (c) HYP3RLINX -  
ApparitionSec  
  
hyp3rlinx  
`