Elcom CommunityManager.NET Auth Bypass Vulnerability 2010-12-20 10:15:55

Elcom CommunityManager.NET Auth Bypass Vulnerability - Security Advisory - SOS-10-004
Release Date. 20-Dec-2010
Last Update. -
Vendor Notification Date. 22-Jan-2010
Product. Elcom Technology's
Platform. IIS with ASP.NET
Affected versions. v6.7 verified and
possibly others.
Severity Rating. High
Impact. Application "System" user access
Attack Vector. Remote without authentication
Solution Status. Vendor patch
CVE reference. Not yet assigned

The web application uses cookie parameters passed via HTTP
requests to identify which user is logged in. Authentication
routines can be bypassed by simply appending the below POC
string to a cookie which already contains a valid ASP.NET
session ID. The value given to the various cookie parameters
indicates the specific user ID for the application user the
attacker wishes to impersonate.

Proof of Concept.
To exploit this vulnerability, simply browse to the software
to automatically create a valid ASP.NET session ID. Once
obtained, add the following to the cookie parameter:

; CMLogUserwww2=21; OnlineLearnUserwww2=21

Note that the ID value of "21" in the above instance
indicates that the user with the user ID of "21" will be
impersonated. If this user ID is not linked to a user account,
access will not be obtained. Some enumeration or educated
guessing may be required.

Sense of Security has been advised that Elcom Technology has
patched all versions of CommunityManager.NET and notified all

Discovered by.
Sense of Security Labs.

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