Web Attacks Using HTTP Parameter Pollution
At the OWASP AppSec Poland 2009 web security conference two Italian security experts presented a new kind of web application attack threat. The presentation slides for the method called HTTP Parameter Pollution (HPP) are now available online.
The new attack class adds yet another method to the known ones attackers have used to inject scripts or SQL queries into HTTP GET or POST requests. Security researchers Stefano Di Paola and Luca Carettoni explain the method in their presentation through the assignment of parameter-value pairs.
The multiple parameter definitions in the following HTTP request can lead to unexpected behavior in web applications:
GET /foo?par1=val1&par1=val2 HTTP/1.1
That depends on the web application. Some take the first parameter value, some the second, others concatenate them and still others build an array.
What begins at HTTP servers ends up in frameworks and applications. Di Paola und Carettoni demonstrate the HTTP Parameter Pollution (HPP) effect on the CUPS print system web interface, during a CPAN search and in the Plone web framework. By the estimation of the two security experts, hard-coded variables can be overwritten with an HPP attack to exploit the vulnerabilities of the program. Even web application firewalls (WAFs) and other detection and repair methods could be outfoxed by the HPP attack under circumstances.
Other presentation slides show how an HPP attack interacts with program code and ties HTTP cookies and URL rewriting into the process. Further practical examples describe attacks on ModSecurity, PHPIDS, the Google Search Appliance and other web search engines, as well as Yahoo! Mail Classic.
Countermeasures suggested by Di Paola and Carettoni include applying URL encoding and using strict regular expressions (regex) with URL rewriting. Above all, they suggest being aware of the weaknesses of individual application components and to use strict filtering. The two have published an extensive white paper on the subject. The presentation slides can be downloaded from the Open Web Application Security Project (OWASP) website.
Comments
comments powered by DisqusIssue 261/2022
Buy this issue as a PDF
News
-
GNOME 43 To Bring Some Exciting New Features
GNOME 43 is getting close to the first alpha development release and it promises to add one particular feature that should be exciting to several users.
-
KaOS 2022.06 Now Available With KDE Plasma 5.25
The newest iteration of KaOS Linux not only adds the latest KDE Plasma desktop but sets LibreOffice as the default.
-
Manjaro 21.3.0 Is Now Available
Manjaro “Ruah” has been released and includes the latest Calamares installer, GNOME 42, and much more.
-
SpiralLinux is a New Linux Distribution Focused on Simplicity
A new Linux distribution, from the creator of GeckoLinux, is a Debian-based operating system with a focus on simplicity and ease of use.
-
HP Dev One Linux Laptop is Now Available for Pre-Order
The System76/HP collaboration Dev One laptop, geared toward developers, is now available for pre-order.
-
NixOS 22.5 Is Now Available
The latest release of NixOS with a much-improved package manager and a user-friendly graphical installer.
-
System76 Teams up with HP to Create the Dev One Laptop
HP and System76 have come together to develop a new laptop, powered by Pop!_OS and aimed toward developers.
-
Titan Linux is a New KDE Linux Based on Debian Stable
Titan Linux is a new Debian-based Linux distribution that features the KDE Plasma desktop with a focus on usability and performance.
-
Danielle Foré Has an Update for elementary OS 7
Now that Ubuntu 22.04 has been released, the team behind elementary OS is preparing for the upcoming 7.0 release.
-
Linux New Media Launches Open Source JobHub
New job website focuses on connecting technical and non-technical professionals with organizations in open source.
greenatmos
We have just added your latest post "Web Attacks Using HTTP Parameter Pollution - Linux Magazine Online" to our <a href="http://www.greenatmos.com"> Directory of Environment </a> . You can check the inclusion of the post <a href="http://greenatmos.com/story...inux-magazine-online"> here </a> . We are delighted to invite you to submit all your future posts to the <a href="http://www.greenatmos.com"> directory </a> for getting a huge base of visitors to your website and gaining a valuable backlink to your site.
Warm Regards
greenatmos.com Team
http://www.greenatmos.com