CVE-2014-2904 in wolfSSL
Summary
by MITRE
wolfssl before 3.2.0 has a server certificate that is not properly authorized for server authentication.
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Analysis
by VulDB Data Team • 02/26/2024
The vulnerability identified as CVE-2014-2904 affects wolfSSL versions prior to 3.2.0 and represents a critical certificate validation flaw that undermines the security of SSL/TLS server authentication. This issue stems from improper certificate authorization checks during the SSL handshake process, potentially allowing malicious actors to present certificates that should not be accepted for server authentication purposes. The flaw specifically impacts the certificate verification mechanism within the wolfSSL library, which is widely used in embedded systems, IoT devices, and various applications requiring secure communication. When a server presents a certificate that fails proper authorization validation, it creates an avenue for man-in-the-middle attacks and certificate spoofing scenarios. The vulnerability resides in the certificate validation logic that does not adequately verify the certificate's intended use for server authentication, particularly concerning the extended key usage extensions that should restrict certificate applicability. This weakness directly violates the fundamental security principles of certificate-based authentication and can lead to complete trust model compromise.
The technical implementation of this vulnerability occurs within the wolfSSL certificate validation routines where the library fails to properly enforce certificate purpose constraints. Specifically, the validation process does not correctly check the extended key usage (EKU) extension within X.509 certificates, which should contain the server authentication key purpose OID. Without proper validation of this extension, certificates with server authentication purposes may be accepted even when they lack the appropriate authorization. The flaw manifests during the SSL/TLS handshake when the server presents its certificate to the client, and the validation routine does not perform adequate checks on the certificate's intended use. This allows certificates that have been issued for other purposes such as code signing or email encryption to be accepted for server authentication, fundamentally undermining the certificate trust model. The vulnerability is classified under CWE-295 which specifically addresses improper certificate validation and certificate chain validation failures, making it a direct descendant of well-known certificate security weaknesses that have plagued SSL/TLS implementations across various platforms.
The operational impact of CVE-2014-2904 extends significantly beyond simple certificate validation failures, creating substantial risk for systems relying on wolfSSL for secure communications. Organizations using affected versions of wolfSSL face potential exposure to active attacks where adversaries can present fraudulent certificates that bypass authentication checks, potentially enabling complete network infiltration. The vulnerability particularly affects embedded systems and IoT devices that often use wolfSSL for lightweight secure communication, making these systems prime targets for attackers seeking to exploit the authentication bypass. In practical attack scenarios, an adversary could intercept communications and present a certificate with proper signatures but lacking server authentication authorization, causing clients to trust fraudulent servers. This weakness also impacts applications where wolfSSL is used for mutual authentication, as the server certificate validation failure could allow unauthorized parties to establish trusted connections. The vulnerability's impact is exacerbated by the fact that many embedded systems do not perform regular security updates, leaving devices vulnerable for extended periods. According to ATT&CK framework domain T1552, this vulnerability enables credential access through compromised authentication mechanisms, while T1046 relates to the network service discovery that attackers might perform using the compromised trust model.
Mitigation strategies for CVE-2014-2904 require immediate action to upgrade to wolfSSL version 3.2.0 or later, which contains the necessary certificate validation fixes. Organizations should conduct comprehensive inventory assessments to identify all systems using vulnerable wolfSSL versions and prioritize updates based on risk exposure. Network monitoring should be enhanced to detect potential certificate validation failures or unusual authentication patterns that might indicate exploitation attempts. Security teams should implement certificate pinning mechanisms where possible to add additional layers of protection beyond the standard certificate validation. System administrators should also review and strengthen certificate management policies to ensure that certificates are properly authorized for their intended use cases. The fix implemented in wolfSSL 3.2.0 addresses the specific validation logic that was bypassing EKU checks and ensures proper enforcement of certificate purpose constraints. Additional defensive measures include implementing certificate transparency monitoring, deploying intrusion detection systems focused on SSL/TLS handshake anomalies, and establishing regular security assessments of cryptographic libraries in use. Organizations should also consider implementing certificate lifecycle management processes that include regular validation of certificate purposes and proper authorization checks to prevent similar vulnerabilities from emerging in the future.