We report several practically-exploitable cryptographic vulnerabilities in the end-to-end encryption in Matrix and describe proof-of-concept attacks exploiting these vulnerabilities. When relying on implementation specific behaviour, these attacks target the Matrix standard as implemented by the matrix-react-sdk and matrix-js-sdk libraries. These libraries provide the basis for the flagship Element client. The vulnerabilities we exploit differ in their nature (insecure by design, protocol confusion, lack of domain separation, implementation bugs) and are distributed broadly across the different subprotocols and libraries that make up the cryptographic core of Matrix.

Status: Whilst the language of the paper and this website is in present tense, many of the vulnerabilities disclosed have been fixed. See our updated paper (or Matrix’ website) for more details. Our updated paper includes details of the mitigations for these attacks (alongside a few updates and corrections).

Chepy is a python library with a handy cli that is aimed to mirror some of the capabilities of CyberChef. A reasonable amount of effort was put behind Chepy to make it compatible to the various functionalities that CyberChef offers, all in a pure Pythonic manner. There are some key advantages and disadvantages that Chepy has over Cyberchef. The Cyberchef concept of stacking different modules is kept alive in Chepy.

A utility which can be used to recover the passphrase for a PGP or GnuPG key.