Sec-Tec Advisory - XSS in Snitz Forums 2000

The most up to date version of this advisory can always be found at:
www.sec-tec.co.uk/vulnerability/snitzxss.html

Advisory creation date:  6th May 2004
Product:    Snitz Forums 2000
Tested version:    3.4.04 (older versions believed to be affected also)
Vulnerability:    XSS
Discoverd by:    Pete Foster - Sec-Tec Ltd (www.sec-tec.co.uk)

Product:
Snitz Forums 2000 is an interactive discussion environment that allows
different people on the Internet or an Intranet to leave messages for each
other, and then reply.

Description:
When registering a new account the register.asp script fails to properly
sanitize the E-mail address (Email) field.  An attacker can enter specially
crafted strings into this field that can allow him to launch cross-site
scripting (XSS) attacks.  Successful exploitation of this could lead to the
theft of sensitive information, such as valid session details.

Affected object:
register.asp

POC Exploit:
When registering a new account (or ammending an existing one), enter the
following as an email address:
p@p" onMouseOver="alert(document.cookie);

When a user then follows a link to send the attacker an email, the script
code is executed.


Fix:
The Email field should be filtered to remove dangerous characters.

The vendor has given details that fixes the symptoms.

--- Vendor quote ---

On line #184 of pop_mail.asp:

Change this:  rs("M_EMAIL")

To this:  chkString(rs("M_EMAIL"),"display")

--- End vendor quote ---

Vendor fix details can also be found at:
http://forum.snitz.com/forum/topic.asp?TOPIC_ID=53360


Release timeline:
Vulnerability discovered:  April 29th 2004
Vendor notified:    May 6th 2004
Vendor response:    June 11th 2004
Public release:      June 16th 2004

If using this document, please link to:
http://www.sec-tec.co.uk/vulnerability/snitzxss.html



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