This article introduces script injection payloads that bypass ASP. NET ValidateRequest filter and also details the hit and trial procedures to analyze. NET debug errors. The techniques included in this article should be used when ValidateRequest is enabled, which is the default setting of ASP. About ValidateRequest: The Microsoft.

Author:Natilar Moogukus
Language:English (Spanish)
Genre:Health and Food
Published (Last):26 May 2010
PDF File Size:14.98 Mb
ePub File Size:3.62 Mb
Price:Free* [*Free Regsitration Required]

By using our site, you acknowledge that you have read and understand our Cookie Policy , Privacy Policy , and our Terms of Service. Information Security Stack Exchange is a question and answer site for information security professionals.

It only takes a minute to sign up. Net has a feature called request validation which detects malicious inputs and blocks the request. By its nature, request validation is not a precise science. OWASP clearly recommend to only rely on request validation as defence-in-depth, not as a security boundary. I am updating a. Sure, I could tell the trainees "don't do it" - but an example is very powerful.

I have found that request validation in. Net 4. Are there any publicly known ways to bypass. The most recent link I found was this. There area a number of places that Request validation may be bypassed, depending on the architecture and function of the application under review, which is likely why Microsoft don't recommend relying on it.

Update Another one that might bypass Request Validation is the use of certain Unicode characters in place of the blocked ones. This can allow for an ASP. I would note that if you are using the default binding providers in ASP.

This could be demonstrated relatively trivially with a simple ASP. Taking the same data and posting it to the same action as JSON via fiddler for example would not result in the same validation. There are known, documented bypasses such as JSON requests that will not be addressed in future releases, and the request validation feature is no longer provided in ASP.

NET vNext. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. How to bypass. Ask Question. Asked 5 years, 4 months ago. Active 1 month ago. Viewed 16k times. To help make this a better question, can you edit the question to tell us what you've tried, what research you've done, and anything you know about how request validation works? There's lots of prior work on bypassing XSS filters see, e. Jan 26 '15 at Thanks for the link, I had not seen that one.

Active Oldest Votes. Data which enters the application via another channel e. Request validation only really helps where data is placed into an HTML context, where it's placed into a JavaScript context for example it won't provide good protection. Request validation doesn't cover all data sent from the client. For example if the application processes data from user HTTP headers e.

User agent it can render the site vulnerable to XSS. Data can enter the application via areas such as file upload, which again won't always trigger request validation. If the page context of the XSS is a tag on an input attribute, e. Paddy Paddy 4 4 bronze badges. Sign up or log in Sign up using Google.

Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast JavaScript is ready to get its own place. Featured on Meta. What posts should be escalated to staff using [status-review], and how do I….

We're switching to CommonMark. Linked Related Hot Network Questions. Question feed.


Microsoft ASP.NET ValidateRequest Filters Bypass Cross-Site Scripting Vulnerability :80/:443

It is possible to bypass the ASP. NET request validation capability [1] when errors are ignored using request encoding techniques described in [2]. This can be abused to perform stored cross-site scripting XSS attacks. Their response was as follows:.


Subscribe to RSS

By using our site, you acknowledge that you have read and understand our Cookie Policy , Privacy Policy , and our Terms of Service. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. If your requirement is to bypass ASP. NET; then in the aspx page directive add the validateRequest attribute and set it to false.

Related Articles