PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWS._load in jwt/api_jws.py is affected because parser catches ValueError but not RecursionError. This occurs when a deeply nested token header reaches json.loads.
As a result, RecursionError escapes the documented PyJWT error hierarchy. Consequently, an unauthenticated malformed token can cause a request-level failure and HTTP 500. This issue is fixed in version 2.14.0.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
Low
Partial disruption
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Pyjwt_Project Pyjwt
cpe:2.3:a:pyjwt_project:pyjwt:2.13.0:*:*:*:*:*:*:*
|
— | — |
References 3
https://github.com/jpadilla/pyjwt/commit/06573692ebcdec8831c3927513b3e87c31fbbb…
security-advisories@github.com
https://github.com/jpadilla/pyjwt/releases/tag/2.14.0
security-advisories@github.com
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-8wjv-2p76-3863
security-advisories@github.com