CVE-2019-6687 in BIG-IP ASM
Summary
by MITRE
On versions 15.0.0-15.0.1.1, the BIG-IP ASM Cloud Security Services profile uses a built-in verification mechanism that fails to properly authenticate the X.509 certificate of remote endpoints.
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Analysis
by VulDB Data Team • 03/16/2024
The vulnerability identified as CVE-2019-6687 affects F5 BIG-IP Application Security Manager (ASM) versions 15.0.0 through 15.0.1.1, specifically within the Cloud Security Services profile functionality. This issue represents a critical authentication failure that undermines the security posture of organizations relying on F5's application delivery controllers for protecting their web applications and APIs. The flaw resides in the certificate verification mechanism that is supposed to validate the authenticity of remote endpoints during secure communications, creating a potential pathway for malicious actors to bypass security controls.
The technical implementation of this vulnerability stems from insufficient certificate validation procedures within the BIG-IP ASM Cloud Security Services profile. When the system attempts to verify X.509 certificates from remote endpoints, it fails to properly validate the certificate chain, allowing potentially untrusted certificates to be accepted as valid. This weak certificate validation process creates a trust relationship that can be exploited by attackers who possess malicious certificates or can manipulate the certificate verification process. The vulnerability essentially allows for man-in-the-middle attacks where attackers can present forged certificates that the system incorrectly accepts as legitimate, thereby undermining the integrity of the secure communication channels.
The operational impact of this vulnerability extends beyond simple certificate validation failures and represents a significant threat to enterprise security infrastructure. Organizations using affected BIG-IP versions may experience unauthorized access to protected applications, data exfiltration, and potential compromise of the entire application delivery chain. The flaw affects cloud security services that are critical for protecting modern web applications, making it particularly dangerous for companies that rely on F5's security solutions for their digital infrastructure. Attackers exploiting this vulnerability could potentially gain access to sensitive data, disrupt services, or establish persistent access points within the network environment.
Security professionals should immediately implement mitigation strategies including upgrading to F5 BIG-IP versions 15.0.1.2 or later, which contain the necessary patches to address the certificate verification flaw. Organizations should also conduct thorough security assessments of their current BIG-IP configurations to identify any potential exploitation attempts and monitor network traffic for suspicious certificate validation patterns. The vulnerability aligns with CWE-295, which addresses improper certificate validation, and represents a significant concern under ATT&CK technique T1566, specifically related to credential harvesting through phishing and other social engineering methods that could leverage this authentication bypass. Additionally, this weakness may contribute to broader attack chains involving credential theft and lateral movement within compromised environments, making prompt remediation essential for maintaining overall security posture.