So you found an web site vulnerable to the ASP.NET Padding Vulnerability, used Minded Security's web.config bruter and now you have the applications web.config file. Now what?

Here's a burp plugin to decrypt FormsAuthentication tokens, allowing you to edit them as a plain-text cookie changing "AuthCookie=AB1351CF[Encrypted and Signed hex blog]D1" to "__bMKUusername=jwpari". The plugin will then re-encrypt and sign the FormsAuthenticationTicket and the ASP.NET application will never know the difference.


BurpMachineKeyUtils-0.1.jar

https://github.com/beersec/BurpMachineKeyUtils/

Follow me on twitter, @jwpari.