Auth bypass in Auth0 Jsonwebtoken

CVE-2022-23540

In versions `<=8.5.1` of `jsonwebtoken` library, lack of algorithm definition in the `jwt.verify()` function can lead to signature validation bypass due to defaulting to the `none` algorithm for signature verification. Users are affected if you do not specify algorithms in the `jwt.verify()` function. This issue has been fixed, please update to version 9.0.0 which removes the default support for the none algorithm in the `jwt.verify()` method. There will be no impact, if you update to version 9.0.0 and you don’t need to allow for the `none` algorithm. If you need 'none' algorithm, you have to explicitly specify that in `jwt.verify()` options.

Vulnerability class: Broken Authentication

EPSS: 0.005 (41.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2022-23540?
CVE-2022-23540 is a medium-severity vulnerability in Auth0 Jsonwebtoken, classified under Improper Authentication. CVSS score: 6.4/10. Published 2022-12-22.
How severe is CVE-2022-23540?
Medium severity. CVSS v3 base score is 6.4 out of 10.
Is CVE-2022-23540 known to be exploited?
8 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.