Globus `identity_provider` restriction ignored when used with `allow_all` in JupyterHub 5.0

Vulnerability Description

OAuthenticator is software that allows OAuth2 identity providers to be plugged in and used with JupyterHub. JupyterHub < 5.0, when used with `GlobusOAuthenticator`, could be configured to allow all users from a particular institution only. This worked fine prior to JupyterHub 5.0, because `allow_all` did not take precedence over `identity_provider`. Since JupyterHub 5.0, `allow_all` does take precedence over `identity_provider`. On a hub with the same config, now all users will be allowed to login, regardless of `identity_provider`. `identity_provider` will basically be ignored. This is a documented change in JupyterHub 5.0, but is likely to catch many users by surprise. OAuthenticator 16.3.1 fixes the issue with JupyterHub 5.0, and does not affect previous versions. As a workaround, do not upgrade to JupyterHub 5.0 when using `GlobusOAuthenticator` in the prior configuration.

References

• https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-gprj-3p75-f996
• https://github.com/jupyterhub/oauthenticator/commit/d1aea05fa89f2beae15ab0fa0b0d071030f79654
• https://jupyterhub.readthedocs.io/en/stable/howto/upgrading-v5.html#authenticator-allow-all-and-allow-existing-users