CVE Vulnerabilities

CVE-2017-11424

Published: Aug 24, 2017 | Modified: Oct 03, 2019
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N
RedHat/V2
RedHat/V3
5.3 MODERATE
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Ubuntu
MEDIUM

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 Software

Name Vendor Start Version End Version
Pyjwt Pyjwt_project * 1.5.0 (including)
Pyjwt Ubuntu devel *
Pyjwt Ubuntu upstream *
Pyjwt Ubuntu xenial *
Pyjwt Ubuntu zesty *

References