HTTP Parameter Pollution

[Stefano Di Paola <stefano.dipaola () wisec it>]

Hi guys,

during OWASP AppSec Poland 2009 we presented a newly discovered input
validation vulnerability called "HTTP Parameter Pollution" (HPP).

Basically, it can be defined as the feasibility to override or add HTTP
GET/POST parameters by injecting query string delimiters.

In the last months, we have discovered several real world flaws in which
HPP can be used to modify the application behaviors, access
uncontrollable variables and even bypass input validation checkpoints
and WAFs rules. 

Exploiting such HPP vulnerabilities, we have found several problems in
some Google Search Appliance front-end scripts, Ask.com, Yahoo! Mail
Classic and many other products.

If you are interested, you are kindly invited to have a look at:  
http://www.owasp.org/images/b/ba/AppsecEU09_CarettoniDiPaola_v0.8.pdf

We're going to release additional materials in the next future,
including a video of the Yahoo! attack vector.

Stay tuned on http://blog.mindedsecurity.com and
http://blog.nibblesec.org

Cheers,
Stefano Di Paola and Luca Carettoni

-- 
Stefano Di Paola
Chief Technology Officer, LA/ISO27001
Minded Security Research Labs Director

Minded Security - Application Security Consulting

Official Site: www.mindedsecurity.com

Personal Blog: www.wisec.it/sectou.php
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