CVEvulnerability

CVE-2021-41194

9.8 CRITICAL Published 2021-10-28 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-10-28
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected])
6.8 MEDIUM — AV:N/AC:M/Au:N/C:P/I:P/A:P
Weaknesses
CWE-284

Description

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. If any users have never logged in with their normalized username (i.e. lowercase), they will still be vulnerable until a patch or upgrade occurs.

Affected configurations

• jupyterhub first use authenticator (< 1.0.0)

Related

Weakness · CWE (1)

  • CWE-284 Improper Access Control weakness

References