`jupyterhub-ltiauthenticator` is a JupyterHub authenticator for learning tools interoperability (LTI). LTI13Authenticator that was introduced in `jupyterhub-ltiauthenticator` 1.3.0 wasn't validating JWT signatures. This is believed to allow the LTI13Authenticator to authorize a forged request. Only users that has configured a JupyterHub installation to use the authenticator class `LTI13Authenticator` are affected. `jupyterhub-ltiauthenticator` version 1.4.0 removes LTI13Authenticator to address the issue. No known workarounds are available.

AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CWE-347

https://github.com/jupyterhub/ltiauthenticator/blob/3feec2e81b9d3b0ad6b58ab4226af640833039f3/ltiauthenticator/lti13/validator.py#L122-L164

https://github.com/jupyterhub/ltiauthenticator/blob/main/CHANGELOG.md#140---2023-03-01

https://github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-mcgx-2gcr-p3hp