CVE-2021-41194 — CRITICAL (9.1)

Q: How severe is CVE-2021-41194?

CVE-2021-41194 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.

Q: Is there a patch for CVE-2021-41194?

Check the references section above for vendor advisories and patch information. Affected products include: Jupyterhub First Use Authenticator.

Vulnerability 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.

CVSS Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

NONE

Affected Products

Vendor	Product	Versions
Jupyterhub	First Use Authenticator	< 1.0.0

Related Weaknesses (CWE)

CWE-284

References

https://github.com/jupyterhub/firstuseauthenticator/pull/38PatchThird Party Advisory
https://github.com/jupyterhub/firstuseauthenticator/pull/38.patchPatchThird Party Advisory
https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvThird Party Advisory
https://github.com/jupyterhub/firstuseauthenticator/pull/38PatchThird Party Advisory
https://github.com/jupyterhub/firstuseauthenticator/pull/38.patchPatchThird Party Advisory
https://github.com/jupyterhub/firstuseauthenticator/security/advisories/GHSA-5xvThird Party Advisory

FAQ

What is CVE-2021-41194?

CVE-2021-41194 is a vulnerability with a CVSS score of 9.1 (CRITICAL). 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 v...

How severe is CVE-2021-41194?

CVE-2021-41194 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2021-41194?

Check the references section above for vendor advisories and patch information. Affected products include: Jupyterhub First Use Authenticator.