PyJWT is a Python implementation of JSON Web Token standards. From 2.11.0 through 2.13.0, PyJWTs PyJWT._merge_options() method can modify a caller-supplied mutable options mapping when verify_signature is false. If an application reuses that same mapping for a later decode() or decode_complete() call and changes verify_signature to true, the mapping can retain false values for expiration, not-before, issued-at, audience, issuer, subject, and JWT ID checks. A signed token with invalid registered claims can then be accepted without disabling signature verification, but applications that create a fresh options mapping for each call are not affected.
Weakness
The product does not properly protect an assumed-immutable element from being modified by an attacker.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Pyjwt | Ubuntu | upstream | * |
Potential Mitigations
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/384.html
- https://cwe.mitre.org/data/definitions/385.html
- https://cwe.mitre.org/data/definitions/386.html
- https://cwe.mitre.org/data/definitions/387.html
- https://cwe.mitre.org/data/definitions/388.html