CVE-2022-31027 — Authorization Bypass Through User-Controlled Key when using CILogonOAuthenticator in oauthenticator

OAuthenticator is an OAuth token library for the JupyerHub login handler. CILogonOAuthenticator is provided by the OAuthenticator package, and lets users log in to a JupyterHub via CILogon. This is primarily used to restrict a JupyterHub only to users of a given institute. The allowed_idps configuration trait of CILogonOAuthenticator is documented to be a list of domains that indicate the institutions whose users are authorized to access this JupyterHub. This authorization is validated by ensuring that the *email* field provided to us by CILogon has a *domain* that matches one of the domains listed in `allowed_idps`.If `allowed_idps` contains `berkeley.edu`, you might expect only users with valid current credentials provided by University of California, Berkeley to be able to access the JupyterHub. However, CILogonOAuthenticator does *not* verify which provider is used by the user to…

Published Jun 6, 2022Updated Apr 23, 2025Sources: cvelistV5, GitHub_M

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

jupyterhub

oauthenticator

CVSS base

4.2

MEDIUM

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

jupyterhub

Products (1)

oauthenticator

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
4.2	CVSS 3.1	MEDIUM	—	—	cvelistV5

Weakness & attack patterns

CWE-639

References

1 on the record

github.com/jupyterhub/oauthenticator/security/advisories/GHSA-r7v4-jwx9-wx43
x_refsource_CONFIRM

Elsewhere on this site

jupyterhubevery CVE for this vendor
CWE-639other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.