[Gosecure Adivsory] Neoteris IVE Vulnerability

[Jian Hui Wang <jhwang@xxxxxxxxxxx>]

                      Gosecure Advisory

                     http://www.gosecure.ca

             Neoteris IVE changepassword.cgi Authentication Bypass


Date Published: 2004-09-20

Date Discovered: 2004-07-23

Advisory ID: GOSECURE-2004-10

Class: Design Error

Risk: Medium

Vendor: Juniper Networks
www.juniper.net

Advisory URL:
http://www.gosecure.ca/SecInfo/gosecure-2004-10.txt


Affected System:

Neoteris Instant Virtual Extranet (IVE) OS, Version 3.x
Netories Instant Virtual Extranet (IVE) OS, Version 4.x  

Description:

Neoteris Instant Virtual Extranet (IVE) is a well known "clientless" SSL VPN 
solution for internal network remote access via standard web browser. It is 
widely used as an extranet portal for corporate network.

There is a vulnerability in Neoteris IVE password management.

When a valid user tries to authenticate via Neoteris and the password is 
expired, the user will be directly forwarded to "changepassword.cgi" without 
asking any form of authentication. The username, authentication server and type 
will be appended to ?changepassword.cgi? URL. Since the "changepassword.cgi" 
allows the user to try the old password as many times as they want, effectively 
allowing brute force password attack. By using the trivial information 
gathering skills to get the valid accounts and launching brute force attack, a 
remote attacker may take over the password expired accounts and gain 
unauthorized access to the internal network resource.

This vulnerability only affects the IVE products which are configured with an 
LDAP or NT domain authentication server. Other type of authentication servers 
are  not affected.

Solution:

Vendor has released a patch and an advisory to address to this vulnerability. 
The advisory is available the following location:
http://www.juniper.net/alerts/viewalert.jsp?actionBtn=Seach&txtAlertNumber=PSN-2004-08-25&viewMode=view

Credits:

The vulnerability was found by Jian Hui Wang from Team Gosecure. Great thank to 
Robert Masse for his support to this issue.

Copyright (c) 2002-2004 GoSecure.Inc

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