CVE-2012-5781 in Elastic Load Balancing API Tools
Summary
by MITRE
Amazon Elastic Load Balancing API Tools does not verify that the server hostname matches a domain name in the subject s Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate, related to overriding the default JDK X509TrustManager.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 02/09/2018
The vulnerability identified as CVE-2012-5781 affects Amazon Elastic Load Balancing API Tools and represents a critical SSL/TLS security flaw that undermines the fundamental principle of certificate validation. This weakness stems from the tools' failure to properly validate SSL certificates against the hostname being connected to, creating a significant attack vector for man-in-the-middle adversaries. The vulnerability specifically targets the X.509 certificate validation process within the Java runtime environment, where the default JDK X509TrustManager implementation is being overridden without proper hostname verification.
The technical flaw manifests in the improper implementation of SSL certificate validation logic where the application accepts any valid certificate regardless of whether it matches the target hostname. This occurs because the tool bypasses the standard certificate validation mechanisms that should ensure the certificate's Common Name (CN) or Subject Alternative Name (SAN) fields contain the domain name corresponding to the server being accessed. The vulnerability falls under CWE-295 which specifically addresses improper certificate validation, and aligns with ATT&CK technique T1046 for network service scanning and T1566 for credential access through social engineering.
The operational impact of this vulnerability is severe as it allows attackers to establish fraudulent SSL connections with valid certificates, effectively enabling them to intercept and potentially modify communications between clients and legitimate servers. An attacker with the capability to present a valid certificate signed by a trusted Certificate Authority could impersonate any legitimate service, making it particularly dangerous in cloud environments where Elastic Load Balancing services are extensively used. The vulnerability affects the integrity and confidentiality of data transmitted through the affected API tools, potentially exposing sensitive information and enabling unauthorized access to cloud resources.
Mitigation strategies should focus on implementing proper hostname verification mechanisms within the application's SSL/TLS configuration. Organizations should ensure that all SSL certificate validation includes strict hostname matching against both the Common Name and Subject Alternative Name fields of certificates. The recommended approach involves configuring the application to use the default JDK X509TrustManager implementation or implementing a custom trust manager that enforces proper hostname verification. Additionally, security patches should be applied to update the Elastic Load Balancing API Tools to versions that correctly implement certificate validation. Network monitoring should be enhanced to detect unusual certificate usage patterns, and organizations should consider implementing certificate pinning mechanisms where appropriate to further strengthen security posture against this class of vulnerability.