CVE-2004-0607 in kame racoon
Summary
by MITRE
the eay_check_x509cert function in kame racoon successfully verifies certificates even when openssl validation fails which could allow remote attackers to bypass authentication.
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Analysis
by VulDB Data Team • 05/25/2019
The vulnerability identified as CVE-2004-0607 resides within the kame racoon implementation of the eay_check_x509cert function, which represents a critical security flaw in the Internet Key Exchange version 2 protocol stack. This issue affects the cryptographic certificate validation process where the system continues to accept X509 certificates even when OpenSSL validation procedures detect failures, creating a significant bypass opportunity for malicious actors. The flaw operates at the intersection of cryptographic validation and authentication mechanisms, specifically within the context of IPsec VPN implementations that rely on proper certificate verification for secure key exchange operations.
The technical root cause of this vulnerability stems from the improper handling of certificate validation results within the racoon daemon's cryptographic subsystem. When OpenSSL performs its certificate validation checks and identifies issues such as expired certificates, mismatched domain names, or invalid signatures, the eay_check_x509cert function fails to properly enforce these validation failures. Instead, the function continues to accept certificates that should be rejected, effectively allowing the system to proceed with authentication processes that should have been terminated due to certificate validation errors. This behavior creates a scenario where attackers can exploit the validation bypass to establish secure connections using compromised or invalid certificates.
The operational impact of this vulnerability extends beyond simple authentication bypass to encompass potential man-in-the-middle attacks and unauthorized access to protected networks. Attackers can leverage this flaw to present forged certificates that would normally be rejected by standard OpenSSL validation but are accepted by the vulnerable racoon implementation. This creates a pathway for remote attackers to establish IPsec tunnels without proper authentication, potentially gaining access to sensitive network resources. The vulnerability is particularly dangerous in environments where certificate-based authentication is critical for network security, as it undermines the fundamental trust model that secure communications rely upon.
This vulnerability aligns with CWE-295, which addresses improper certificate validation, and represents a specific instance of weak cryptographic practices in certificate handling. The flaw demonstrates poor security implementation where the system fails to properly integrate with established cryptographic libraries, creating a gap between the validation performed by OpenSSL and the acceptance criteria within the racoon daemon. From an ATT&CK framework perspective, this vulnerability maps to T1552.001 - Unsecured Credentials and T1071.004 - Application Layer Protocol: DNS, as attackers can exploit the certificate validation bypass to establish unauthorized secure communications. Organizations using kame racoon implementations are particularly at risk, as the vulnerability affects the core authentication mechanisms that protect network access and data integrity in IPsec environments.
Mitigation strategies for this vulnerability require immediate patching of the racoon implementation to properly enforce OpenSSL validation results and ensure that certificate validation failures are correctly handled. System administrators should implement certificate monitoring solutions that can detect and alert on certificate validation bypass attempts, while also reviewing and strengthening certificate management policies. The recommended approach involves upgrading to patched versions of kame racoon, implementing additional validation layers, and conducting thorough security audits of all IPsec implementations to identify similar validation bypass vulnerabilities. Network segmentation and additional authentication mechanisms should be deployed as compensating controls while patches are being applied to ensure continued security posture during the remediation process.