Community Server - Stored Cross-Site Scripting in User's Signature

From: Advisories PontoSec <>
Subject: Community Server - Stored Cross-Site Scripting in User's Signature

Community Server - Stored Cross-site Scripting in user's signature.

- Product description:
Community Server is a communities and collaboration web application
developed by Telligent.
It uses ASP.NET platform (C#) and Microsoft SQL Server database. From
it's 5.0 version, the software was renamed to Telligent Community.

- Vulnerability Details:
It is possible to insert scripts (Cross-site Scripting) in user's
signature, using BBCode Tag's processing errors.

- Proof of Concept:
Set an user's signature to:

[img]invalid.jpg[url= onerror=alert(1) z=] a[/url][/img]

An alert will be show in every topic the user posts in and also in its profile.

- Affected Versions:
Community Server 2007
(may affect others)

- Unaffected Versions:
Telligent Community 5.x or earlier

- Timeline:
[05/25/10] Vulnerability details sent to address for security related
contacts present at company's website, although the address did not
[05/26/10] Ticket opened asking for contact to send off vulnerability details.
[05/26/10] Ticket's answer received, containing e-mail for the sending
of vulnerability details.
[05/26/10]Vulnerability details sent.
[05/26/10] Answer received informing that vulnerability did not exist
on latest versions of the product.
[07/15/11] Advisory published.

- Credits:
PontoSec - Segurana da Informao < > -
Researcher: Gabriel Lima (gabriel <at>

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