JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to versions 4.1.6 and 5.1.0, if a user is granted the `admin:users` scope, they may escalate their own privileges by making themselves a full admin user. The impact is relatively small in that `admin:users` is already an extremely privileged scope only granted to trusted users. In effect, `admin:users` is equivalent to `admin=True`, which is not intended. Note that the change here only prevents escalation to the built-in JupyterHub admin role that has unrestricted permissions. It does not prevent users with e.g. `groups` permissions from granting themselves or other users permissions via group membership, which is intentional. Versions 4.1.6 and 5.1.0 fix this issue.
https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-9x4q-3gxw-849f
https://github.com/jupyterhub/jupyterhub/commit/ff2db557a85b6980f90c3158634bf924063ab8ba
https://github.com/jupyterhub/jupyterhub/commit/99e2720b0fc626cbeeca3c6337f917fdacfaa428
Published: 2024-08-08
Updated: 2024-08-12
Base Score: 8.3
Vector: CVSS2#AV:N/AC:L/Au:M/C:C/I:C/A:C
Severity: High
Base Score: 7.2
Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Severity: High
Base Score: 8.6
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: High