// For flags

CVE-2022-31027

Authorization Bypass Through User-Controlled Key when using CILogonOAuthenticator in oauthenticator

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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 login, only the email address provided. So a user can login with a GitHub account that has email set to `<something>@berkeley.edu`, and that will be treated exactly the same as someone logging in using the UC Berkeley official Identity Provider. The patch fixing this issue makes a *breaking change* in how `allowed_idps` is interpreted. It's no longer a list of domains, but configuration representing the `EntityID` of the IdPs that are allowed, picked from the [list maintained by CILogon](https://cilogon.org/idplist/). Users are advised to upgrade.

OAuthenticator es una biblioteca de tokens OAuth para el administrador de inicio de sesión de JupyerHub. CILogonOAuthenticator es proporcionado por el paquete OAuthenticator, y permite a usuarios iniciar sesión en un JupyterHub por medio de CILogon. Es usado principalmente para restringir un JupyterHub sólo a usuarios de un determinado instituto. El rasgo de configuración allowed_idps de CILogonOAuthenticator está documentado para ser una lista de dominios que indican las instituciones cuyos usuarios están autorizados a acceder a este JupyterHub. Esta autorización es comprobada al asegurarse de que el campo *email* que nos proporciona CILogon presenta un *dominio* que coincide con uno de los dominios listados en "allowed_idps".Si "allowed_idps" contiene "berkeley.edu", se podría esperar que sólo usuarios con credenciales válidas actuales proporcionadas por la Universidad de California, Berkeley, puedan acceder al JupyterHub. Sin embargo, CILogonOAuthenticator *no* verifica qué proveedor usa el usuario para iniciar sesión, sólo la dirección de correo electrónico proporcionada. Así que un usuario puede iniciar sesión con una cuenta de GitHub que tenga el correo electrónico configurado como "(something)@berkeley.edu", y eso será tratado exactamente igual que alguien que inicie sesión usando el proveedor de identidad oficial de UC Berkeley. El parche que corrige este problema hace un *cambio radical* en la interpretación de "allowed_idps". Ya no es una lista de dominios, sino una configuración que representa el "EntityID" de los IdPs que están permitidos, escogidos de la [lista mantenida por CILogon](https://cilogon.org/idplist/). Es recomendado a usuarios actualizar

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2022-05-18 CVE Reserved
  • 2022-06-06 CVE Published
  • 2023-12-28 EPSS Updated
  • 2024-08-03 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-639: Authorization Bypass Through User-Controlled Key
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Jupyter
Search vendor "Jupyter"
Oauthenticator
Search vendor "Jupyter" for product "Oauthenticator"
< 15.0.0
Search vendor "Jupyter" for product "Oauthenticator" and version " < 15.0.0"
-
Affected