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From David Ong <da...@postboy.net>
Subject config/9385: ScriptAlias problem allows .exe's in the scriptaliased directory to be executed
Date Sun, 06 Jan 2002 16:08:21 GMT

>Number:         9385
>Category:       config
>Synopsis:       ScriptAlias problem allows .exe's in the scriptaliased directory to be
executed
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Sun Jan 06 08:10:01 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     david@postboy.net
>Release:        1.3.22
>Organization:
apache
>Environment:
Apache 1.3.22 for Win32 on Win2000 SP2
>Description:
 From: http://www.securiteam.com/windowsntfocus/5ZP030U60U.html

As advised in the installation text that comes with all versions of PHP, when installing PHP.EXE
for use on a windows machine installed with Apache, the user should insert a few lines of
code into the Apache "httpd.conf". These exact lines are shown here:
   ScriptAlias /php/ "c:/php/"
   AddType application/x-httpd-php .php
   Action application/x-httpd-php "/php/php.exe"
A security vulnerability arises when placing the ScriptAlias line above. This line effectively
maps the alias /php/ to your web document root such that typing "http://www.example.com/php/"
will actually try to access in this case "c:\php\". Please note that the last "/" on the end
of the URL has to exist for this to work ("http://www.example.com/php" will not work). At
this point your server will respond with "Access Denied", however if you now specify the URL
"http://www.example.com/php/php.exe" , you will see the error "No input file specified". This
error is actually returned by php.exe, which you have just executed on the server.
There are many exploits that can happen with this setup (some very serious, which could be
used to gain root access).

 Details 
Exploit 1: 
It is possible to read any file remotely on the server, even across drives with the following
URL construct:

 "http://www.example.com/php/php.exe?c:\winnt\repair\sam"

PHP.EXE will parse the sam file "c:\winnt\repair\sam" and return it to the browser for download
(this is the Windows NT password file).

 "http://www.example.com/php/php.exe?d:\winnt\repair\sam"

PHP.EXE will return the same file on the D: drive.

The above SAM file can then be used to decrypt all the Account Passwords for the Server.

Exploit 2: 
If you specify a file that exists in the php directory (different files exist depending on
the version of PHP), the web server will try to execute this file and will throw back an error
reporting the install directory of php. So in PHP4, for example, you would specify the following
line:

 "http://www.example.com/php/php4ts.dll"

The error returned by the web server would be: " couldn't create child process: 22693: C:/php/php4ts.dll
" showing the install path of PHP.
>How-To-Repeat:
http://www.example.com/php4/php.exe?c:\winnt\repair\sam
>Fix:

>Release-Note:
>Audit-Trail:
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