Auth bypass in Auth0 Omniauth-Auth0

CVE-2020-15240

omniauth-auth0 (rubygems) versions >= 2.3.0 and < 2.4.1 improperly validate the JWT token signature when using the `jwt_validator.verify` method. Improper validation of the JWT token signature can allow an attacker to bypass authentication and authorization. You are affected by this vulnerability if all of the following conditions apply: 1. You are using `omniauth-auth0`. 2. You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow. The issue is patched in version 2.4.1.

Vulnerability class: Broken Authentication

EPSS: 0.008 (53.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-15240?
CVE-2020-15240 is a high-severity vulnerability in Auth0 Omniauth-Auth0, classified under Improper Authentication. CVSS score: 7.4/10. Published 2020-10-21.
How severe is CVE-2020-15240?
High severity. CVSS v3 base score is 7.4 out of 10.