OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. Prior to 4.0.0, the client_credentials and Resource Owner Password Credentials token grant handlers can authenticate request.client as one confidential client while retaining an attacker-supplied request.client_id for validate_grant_type and validate_scopes. A lower-privilege authenticated client can therefore cause grant and scope authorization to use another client's identity when an application validator relies on the documented client_id argument, potentially issuing tokens with unauthorized grants or scopes.
Validators that authorize exclusively from request.client may not be affected. This issue is fixed in version 4.0.0.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/oauthlib/oauthlib/commit/c951a1d09f99f14e3240973fa83c4f4287d…
security-advisories@github.com
https://github.com/oauthlib/oauthlib/pull/920
security-advisories@github.com
https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0
security-advisories@github.com
https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c
security-advisories@github.com