Vulnerability in Pyjwt Project
CVE-2017-11424
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.018 (78.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000
Affected products
- Pyjwt Project
- Debian Linux — versions 8.0, 9.0
Public proof-of-concept exploits
References
- www.debian.org/security/2017/dsa-3979 (vendor-advisory, Third Party Advisory)
- github.com/jpadilla/pyjwt/pull/277 (Patch, Third Party Advisory, Issue Tracking)
Frequently asked questions
- What is CVE-2017-11424?
- CVE-2017-11424 is a high-severity vulnerability in Pyjwt Project. CVSS score: 7.5/10. Published 2017-08-24.
- How severe is CVE-2017-11424?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2017-11424 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.