CVEvulnerability

CVE-2017-11424

7.5 HIGH Published 2017-08-24 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2017-08-24
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.0 ([email protected])
7.5 HIGH — CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 2.0 ([email protected])
5.0 MEDIUM — AV:N/AC:L/Au:N/C:N/I:P/A:N

Description

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.

Affected configurations

• pyjwt project pyjwt (<= 1.5.0) • debian debian linux 8.0 • debian debian linux 9.0

References