JWTXploiter – A tool to test security of json web token



A tool to test security of JSON Web Tokens. Test a JWT against all known CVEs;

  • Tamper with the token payload: changes claims and subclaims values.
  • Exploit known vulnerable header claims (kid, jku, x5u)
  • Verify a token
  • Retrieve the public key of your target’s ssl connection and try to use it in a key confusion attack with one option only
  • All JWAs supported
  • Generates a JWK and insert it in the token header
  • And much, much more!


  • Read the wiki! wiki


N.B. Cloning the repository should be avoided except for development purposes! N.B. Deb package has to be considered beta

With rpm:

wget http://andreatedeschi.uno/jwtxploiter/jwtxploiter-1.1-1.noarch.rpm

sudo rpm --install jwtxploiter-1.1-1.noarch.rpm

With pip:

sudo pip install jwtxploiter

With deb:

wget http://andreatedeschi.uno/jwtxploiter/jwtxploiter_1.1-1_all.deb
sudo dpkg -i jwtxploiter_1.1-1_all.deb

Cloing the repo:

git clone https://github.com/DontPanicO/jwtXploiter.git

N.B. python3-pip package is required to install dependencies, be sure to have it installed.

Who this tool is written for?

  • Web Application Penetration Tester / Bug Bounty Hunters
    • This tool has been written with the aim of become a key part of pentesters toolkit.
  • Devs who need to test the secuirty of JWTs used in their applications
  • CTF Players
  • Not For Students
    • Since this tool automates lot of stuff, without force the user to know what’s happening under the hood, it won’t help you to understand the vulnerabilities it exploits.

To Know

  • For attacks that generates a jwks file, you could find it in the current working directory. Remeber to deletes such files in order to avoid conflicts.
  • For jku/x5u injection that needs to merge two urls (the server vulnerable url and your one), the HERE keyword is required.
  • For redirect attacks the keyword should replace the redirect url, e.g.
http://app. com/foo?redirect=bar&some=thing --> http://app. com/foo?redirect=HERE&some=thing
  • For jku/x5u injections via HTTP header injection attacks, the HERE keyword sould be appended to the vulnerable parameter, without replacing its value, e.g.
http://app. com/foo?param=value --> http://app. com/foo?param=valueHERE
  • Also, in such cases, be sure to pass the server url and your one as comma separated values.
  • ‘/.well-known/jwks.json’ is automatically appended to your url in jku/x5u attacks. So make sure to place the jwks file under this path on your server.
  • If you don’t want that happen, use the –manual option, but this option is compatible only with –jku-basic and –x5u-basic so, you will need to manually craft the url and pass it to those options, even for attacks that exploit Open Redirect or HTTP header injection.
  • Look at the wiki for a detailed documentation.