CVE-2018-6874 in Auth0
Summary
by MITRE
CSRF exists in the Auth0 authentication service through 14591 if the Legacy Lock API flag is enabled.
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Analysis
by VulDB Data Team • 01/22/2020
The vulnerability identified as CVE-2018-6874 represents a cross-site request forgery weakness within the Auth0 authentication service affecting versions up to 14591. This security flaw specifically manifests when the Legacy Lock API flag is enabled, creating a dangerous condition where authenticated users can be tricked into executing unintended actions on the Auth0 platform without their knowledge or consent. The vulnerability stems from the absence of proper anti-CSRF protection mechanisms in the legacy authentication flow, which was designed to maintain backward compatibility with older client applications but inadvertently introduced significant security risks.
The technical implementation of this vulnerability occurs through the Legacy Lock API's handling of authentication requests. When enabled, this API component fails to validate the origin of authentication requests properly, allowing malicious actors to craft specially crafted web pages or links that, when visited by an authenticated user, automatically submit requests to the Auth0 service. The flaw operates at the application layer where session management and request validation mechanisms are insufficient to distinguish between legitimate user-initiated requests and those crafted by attackers. This weakness aligns with CWE-352, which specifically addresses Cross-Site Request Forgery vulnerabilities in web applications.
The operational impact of CVE-2018-6874 extends beyond simple session hijacking scenarios, as it can potentially enable attackers to perform unauthorized administrative actions within the Auth0 tenant environment. An attacker could exploit this vulnerability to modify user permissions, reset passwords, add or remove applications, or manipulate authentication settings that affect the entire authentication infrastructure. The risk is particularly elevated because Auth0 serves as a central authentication service for numerous applications and platforms, meaning a successful exploitation could compromise multiple downstream systems that rely on the compromised Auth0 tenant. This vulnerability directly maps to several ATT&CK techniques including T1566 for social engineering and T1078 for valid accounts, as it leverages authenticated sessions to perform unauthorized operations.
Organizations using Auth0 with the Legacy Lock API flag enabled face significant exposure to this vulnerability, particularly those with high-value authentication infrastructure or those serving multiple applications that depend on the same Auth0 tenant. The remediation approach requires immediate disabling of the Legacy Lock API flag in affected configurations, which effectively mitigates the vulnerability by removing the insecure authentication path. Additionally, organizations should implement proper CSRF token validation mechanisms, conduct comprehensive security assessments of their authentication flows, and ensure all client applications are updated to use the modern authentication APIs. Security teams should also monitor for potential exploitation indicators such as unusual authentication patterns or unauthorized configuration changes. The vulnerability underscores the importance of regularly reviewing and disabling deprecated features that introduce security risks, as highlighted in industry best practices for maintaining secure authentication systems and aligning with security frameworks that emphasize the principle of least privilege and secure configuration management.