CVE-2021-41194 – Improper Access Control in jupyterhub-firstuseauthenticator

https://notcve.org/view.php?id=CVE-2021-41194

FirstUseAuthenticator is a JupyterHub authenticator that helps new users set their password on their first login to JupyterHub. When JupyterHub is used with FirstUseAuthenticator, a vulnerability in versions prior to 1.0.0 allows unauthorized access to any user's account if `create_users=True` and the username is known or guessed. One may upgrade to version 1.0.0 or apply a patch manually to mitigate the vulnerability. For those who cannot upgrade, there is no complete workaround, but a partial mitigation exists. One can disable user creation with `c.FirstUseAuthenticator.create_users = False`, which will only allow login with fully normalized usernames for already existing users prior to jupyterhub-firstuserauthenticator 1.0.0. • https://github.com/jupyterhub/firstuseauthenticator/pull/38 https://github.com/jupyterhub/firstuseauthenticator/pull/38.patch https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvc-vgmp-jgc3 • CWE-284: Improper Access Control •