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What is ViewState parameter?
The ViewState parameter is a base64 serialised parameter that is normally sent via a hidden parameter called __VIEWSTATE with a POST request. This parameter is deserialised on the server-side to retrieve the data. It is normally possible to run code on a web server where a valid ViewState can be forged.
How do I decrypt ViewState?
11 Answers. Use Fiddler and grab the view state in the response and paste it into the bottom left text box then decode. This worked on an input on which the Ignatu decoder failed with “The serialized data is invalid” (although it leaves the BinaryFormatter-serialized data undecoded, showing only its length).
What is a ViewState in asp net?
View state is the method that the ASP.NET page framework uses to preserve page and control values between round trips. When the HTML markup for the page is rendered, the current state of the page and values that must be retained during postback are serialized into base64-encoded strings.
What is EnableViewStateMAC in asp net?
A view-state MAC is an encrypted version of the hidden variable that a page’s view state is persisted to when the page is sent to the browser. When this property is set to true , the encrypted view state is checked to verify that it has not been tampered with on the client.
How do I view ViewState?
How to view information in ViewState using ASP.NET 2.0 and 3.5
- Step 1: Create an asp.net application with 2 textboxes, a label and a button as shown below.
- Step 2: Add the button click event:
- Step 3: Execute the page and enter some values in the textbox.
- Step 4: Shown above in the blue colored text is the viewstate.
What is .NET ViewState?
How does VIEWSTATE protect against a malicious attacker?
If you use a ViewStateUserKey, then the key used is specific to the particular user. This means that a malicious attacker Mandy cannot learn a valid value of the MAC digest for user Bob. Mandy cannot guess it, because a MAC algorithm is designed to prevent guessing the MAC digest.
Is there a VIEWSTATE vulnerability in ASP.NET?
At the time of writing this blog post, the following well known web application scanners had rated the “ASP.NET ViewState without MAC enabled” vulnerability with low and medium severity which shows the lack of awareness in this area:
How does VIEWSTATE protect against CSRF in ASP.NET?
According to the OWASP CSRF Cheat Sheet viewStateUserKey for ASP.NET ViewState is acceptable to prevent csrf attacks, but I really don’t get how.
Is it good design to encrypt the VIEWSTATE?
To reduce the chance of someone intercepting the information stored in the ViewState, it is good design to encrypt the ViewState.The target web application doesn’t use encryption on ViewState data.