In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: duo

Published: 2017-08-24T16:00:00

Updated: 2024-08-05T18:12:39.550Z

Reserved: 2017-07-18T00:00:00

Link: CVE-2017-11424

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2017-08-24T16:29:00.197

Modified: 2019-10-03T00:03:26.223

Link: CVE-2017-11424

cve-icon Redhat

Severity : Moderate

Publid Date: 2017-06-22T00:00:00Z

Links: CVE-2017-11424 - Bugzilla