CVE-2020-26250
In oauthenticator from version 0.12.0 and before 0.12.2, the deprecated (in jupyterhub 1.2) configuration `Authenticator.whitelist`, which should be transparently mapped to `Authenticator.allowed_users` with a warning, is instead ignored by…
Does this matter?
Lower severity and a low EPSS score (1.13%). Track it; it rarely justifies an emergency change on its own.
Description
OAuthenticator is an OAuth login mechanism for JupyterHub. In oauthenticator from version 0.12.0 and before 0.12.2, the deprecated (in jupyterhub 1.2) configuration `Authenticator.whitelist`, which should be transparently mapped to `Authenticator.allowed_users` with a warning, is instead ignored by OAuthenticator classes, resulting in the same behavior as if this configuration has not been set. If this is the only mechanism of authorization restriction (i.e. no group or team restrictions in configuration) then all authenticated users will be allowed. Provider-based restrictions, including deprecated values such as `GitHubOAuthenticator.org_whitelist` are **not** affected. All users of OAuthenticator 0.12.0 and 0.12.1 with JupyterHub 1.2 (JupyterHub Helm chart 0.10.0-0.10.5) who use the `admin.whitelist.users` configuration in the jupyterhub helm chart or the `c.Authenticator.whitelist` configuration directly. Users of other deprecated configuration, e.g. `c.GitHubOAuthenticator.team_whitelist` are **not** affected. If you see a log line like this and expect a specific list of allowed usernames: "[I 2020-11-27 16:51:54.528 JupyterHub app:1717] Not using allowed_users. Any authenticated user will be allowed." you are likely affected. Updating oauthenticator to 0.12.2 is recommended. A workaround is to replace the deprecated `c.Authenticator.whitelist = ...` with `c.Authenticator.allowed_users = ...`. If any users have been authorized during this time who should not have been, they must be deleted via the API or admin interface, per the referenced documentation.
- CVSS 3.1
- 6.3 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 1.13% probability · 65th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863
- Affected
- jupyter/oauthenticator
- Source
- security-advisories@github.com
References
- https://github.com/jupyterhub/oauthenticator/blob/master/docs/source/changelog.md#0122---2020-11-30Release Notes, Third Party Advisory
- https://github.com/jupyterhub/oauthenticator/commit/a4aac191c16cf6281f3d346615aefa75702b02d7Patch, Third Party Advisory
- https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-384w-5v3f-q499Third Party Advisory
- https://jupyterhub.readthedocs.io/en/1.2.2/getting-started/authenticators-users-basics.html#add-or-remove-users-from-the-hubThird Party Advisory
- https://github.com/jupyterhub/oauthenticator/blob/master/docs/source/changelog.md#0122---2020-11-30Release Notes, Third Party Advisory
- https://github.com/jupyterhub/oauthenticator/commit/a4aac191c16cf6281f3d346615aefa75702b02d7Patch, Third Party Advisory
- https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-384w-5v3f-q499Third Party Advisory
- https://jupyterhub.readthedocs.io/en/1.2.2/getting-started/authenticators-users-basics.html#add-or-remove-users-from-the-hubThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.