CVE-2016-10525 in hapi-auth-jwt2
Summary
by MITRE
When attempting to allow authentication mode `try` in hapi, hapi-auth-jwt2 version 5.1.1 introduced an issue whereby people could bypass authentication.
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Analysis
by VulDB Data Team • 03/17/2023
The vulnerability CVE-2016-10525 represents a critical authentication bypass flaw in the hapi-auth-jwt2 plugin version 5.1.1, which is commonly used within the hapi.js web framework ecosystem for implementing jwt-based authentication mechanisms. This issue specifically manifests when the authentication mode is configured to `try`, a setting that should theoretically attempt authentication but fall back to allowing access when authentication fails. The flaw arises from improper handling of the authentication flow during these fallback scenarios, creating a security gap that malicious actors can exploit to gain unauthorized access to protected resources. The vulnerability directly impacts the integrity of the authentication system by allowing unauthenticated requests to proceed as if they were properly authenticated, undermining the fundamental security posture of applications relying on this plugin.
The technical root cause of this vulnerability lies in the flawed implementation of the authentication mode `try` within the hapi-auth-jwt2 plugin. When this mode is activated, the plugin should attempt to validate jwt tokens and only grant access if validation succeeds, while gracefully falling back to allowing access when authentication fails. However, the implementation contains a logic error where the fallback mechanism does not properly validate whether the request should actually be permitted access. This creates a scenario where even when jwt validation fails or when no valid token is provided, the system continues to process the request as if authentication were successful, effectively disabling the authentication check for certain request paths. The flaw essentially allows any request to proceed through the authentication layer without proper verification, as the plugin fails to enforce the intended security controls during the fallback process.
The operational impact of CVE-2016-10525 extends beyond simple unauthorized access, as it fundamentally undermines the security model of applications using hapi-auth-jwt2 with the `try` authentication mode. Attackers can exploit this vulnerability to bypass authentication entirely for specific endpoints, potentially gaining access to sensitive data, administrative functions, or other protected resources that should require valid jwt authentication. This vulnerability is particularly dangerous in environments where the `try` mode is used for specific endpoints that should remain protected, as it creates a backdoor that allows attackers to access these resources without proper credentials. The impact is compounded because the vulnerability is not immediately obvious during normal operation, making it difficult to detect and remediate without specific security testing focused on authentication bypass scenarios.
Security mitigations for CVE-2016-10525 primarily involve upgrading the hapi-auth-jwt2 plugin to a patched version that properly implements the `try` authentication mode without creating authentication bypass opportunities. Organizations should immediately assess their deployment of this plugin and verify that all instances using the `try` authentication mode are updated to versions that address this vulnerability. Additionally, security teams should implement monitoring for unauthorized access attempts and conduct thorough penetration testing to identify any potential exploitation of this vulnerability in their specific environments. The vulnerability aligns with CWE-284, which addresses improper access control, and maps to ATT&CK technique T1078 for valid accounts, as the bypass allows attackers to operate under the assumption of legitimate authentication. Organizations should also consider implementing additional security controls such as request logging, access control reviews, and authentication monitoring to detect and prevent exploitation of similar authentication bypass vulnerabilities in their systems.