CVE-2017-6143 in BIG-IP
Summary
by MITRE
X509 certificate verification was not correctly implemented in the IP Intelligence Subscription and IP Intelligence feed-list features, and thus the remote server's identity is not properly validated in F5 BIG-IP 12.0.0-12.1.2, 11.6.0-11.6.2, or 11.5.0-11.5.5.
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Analysis
by VulDB Data Team • 02/28/2023
The vulnerability identified as CVE-2017-6143 represents a critical flaw in the cryptographic certificate validation mechanism within F5 BIG-IP systems. This weakness specifically impacts the IP Intelligence Subscription and IP Intelligence feed-list features, which are designed to provide threat intelligence and reputation-based filtering capabilities. The improper implementation of X509 certificate verification creates a fundamental security gap that allows malicious actors to potentially bypass authentication and authorization controls. The affected versions span multiple release branches including 12.0.0 through 12.1.2, 11.6.0 through 11.6.2, and 11.5.0 through 11.5.5, indicating this vulnerability has persisted across several major releases of the F5 BIG-IP platform. This widespread impact suggests the flaw originated from a core architectural component rather than being isolated to specific modules or features.
The technical implementation error manifests in the certificate validation process where the system fails to properly validate the remote server's identity during secure communications. This weakness falls under the category of improper certificate validation as defined by CWE-295, which specifically addresses issues with certificate validation and trust chain verification. The flaw allows for potential man-in-the-middle attacks where attackers can present fraudulent certificates that would be accepted by the system due to insufficient validation checks. When the IP Intelligence features attempt to establish secure connections with external threat intelligence feeds, the system's inability to properly verify certificate authenticity creates an attack surface that adversaries can exploit to intercept communications or inject malicious data into the threat intelligence pipeline.
The operational impact of this vulnerability extends beyond simple authentication failures and represents a significant threat to network security operations. Organizations relying on F5 BIG-IP systems for threat intelligence and reputation-based filtering may experience compromised security posture when the system fails to validate the identity of external intelligence feeds. This could lead to the acceptance of malicious threat intelligence data, potentially causing the network to block legitimate traffic or fail to block known malicious entities. The vulnerability particularly affects security operations centers that depend on accurate threat intelligence for making critical security decisions, as compromised intelligence feeds could result in false positives or negatives that undermine the effectiveness of the entire security infrastructure. Attackers exploiting this vulnerability could potentially redirect traffic through malicious servers or manipulate threat intelligence data to evade detection mechanisms.
Mitigation strategies for CVE-2017-6143 require immediate attention from network security administrators and system operators. The primary recommendation involves applying the official F5 security patches and updates released to address the certificate validation flaw in the affected versions. Organizations should also implement additional monitoring and logging mechanisms to detect potential exploitation attempts, particularly focusing on unusual certificate validation events or connections to unexpected external endpoints. Network segmentation and firewall rules should be reviewed to limit access to the vulnerable IP Intelligence features and restrict outbound connections to known legitimate threat intelligence feeds only. The implementation of certificate pinning for external connections and enhanced logging of certificate validation failures can provide additional layers of protection while waiting for official patches. This vulnerability demonstrates the critical importance of proper certificate validation in security infrastructure components and aligns with ATT&CK technique T1566 which covers credential harvesting through various attack vectors including man-in-the-middle and certificate manipulation tactics. Organizations should also consider implementing network traffic analysis to detect anomalous behavior patterns that might indicate exploitation attempts.