Omniauth Auth0
CVE-2020-15240
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication mechanism validation
MITRE ATT&CK
2 techniques across 2 tactics: Defense Evasion, Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.1 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | A remote attacker could bypass authentication mechanisms to gain unauthorized access by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
omniauth-auth0 (rubygems) versions >= 2.3.0 and < 2.4.1 improperly validate the JWT token signature when using the jwt_validator.verify method. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Improper Authentication vulnerability could allow attackers to bypass authentication mechanisms to gain unauthorized access.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Implement multi-factor authentication, enforce strong password policies, use proven authentication frameworks.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in rubygems
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Improper Authentication (CWE-287), which allows attackers to bypass authentication mechanisms to gain unauthorized access. 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. Affected products include: Auth0 Omniauth-Auth0. Version information: version 2.4.1..
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
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.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Exploit-DB