CVE-2020-26250
JupyterHub OAuthenticator Whitelist Bypass
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.
INFO
Published Date :
Dec. 1, 2020, 9:15 p.m.
Last Modified :
Dec. 8, 2020, 5:50 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
4.0
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2020-26250.
| URL | Resource |
|---|---|
| https://github.com/jupyterhub/oauthenticator/blob/master/docs/source/changelog.md#0122---2020-11-30 | Release Notes Third Party Advisory |
| https://github.com/jupyterhub/oauthenticator/commit/a4aac191c16cf6281f3d346615aefa75702b02d7 | Patch Third Party Advisory |
| https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-384w-5v3f-q499 | Third Party Advisory |
| https://jupyterhub.readthedocs.io/en/1.2.2/getting-started/authenticators-users-basics.html#add-or-remove-users-from-the-hub | Third Party Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2020-26250 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2020-26250 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Dec. 08, 2020
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:M/Au:S/C:P/I:N/A:N) Added CVSS V3.1 NIST AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N Changed Reference Type https://github.com/jupyterhub/oauthenticator/blob/master/docs/source/changelog.md#0122---2020-11-30 No Types Assigned https://github.com/jupyterhub/oauthenticator/blob/master/docs/source/changelog.md#0122---2020-11-30 Release Notes, Third Party Advisory Changed Reference Type https://github.com/jupyterhub/oauthenticator/commit/a4aac191c16cf6281f3d346615aefa75702b02d7 No Types Assigned https://github.com/jupyterhub/oauthenticator/commit/a4aac191c16cf6281f3d346615aefa75702b02d7 Patch, Third Party Advisory Changed Reference Type https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-384w-5v3f-q499 No Types Assigned https://github.com/jupyterhub/oauthenticator/security/advisories/GHSA-384w-5v3f-q499 Third Party Advisory Changed Reference Type https://jupyterhub.readthedocs.io/en/1.2.2/getting-started/authenticators-users-basics.html#add-or-remove-users-from-the-hub No Types Assigned https://jupyterhub.readthedocs.io/en/1.2.2/getting-started/authenticators-users-basics.html#add-or-remove-users-from-the-hub Third Party Advisory Added CWE NIST CWE-863 Added CPE Configuration OR *cpe:2.3:a:jupyter:oauthenticator:*:*:*:*:*:*:*:* versions from (including) 0.12.0 up to (excluding) 0.12.2
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2020-26250 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2020-26250
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.17 }} 0.00%
score
0.52702
percentile