###What is JSON Web Token?

JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed. JWTs can be signed using a secret (with the HMAC algorithm) or a public/private key pair using RSA.

A JSON Web Token [JWT] consists of three parts; an encoded Header, an encoded Payload and the Signature as shown below:

JWT-Br34k3r is an exploit for some APIs (API v2 ) today that implementing a more powerful security model using JSON Web Tokens . The exploit mainly for elevation the privilege and it is based upon enumerate existing users ID and elevation the privilege with having two option for :

First : Brute Force the securit Key and create new Authorization Signature with new privilege .

Second : Bypass JWT Authorization with initialise the algorithm used as None and eliminate the securit key part of the payload.

Copyright 2017 Chouaib Hm

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