CVE-2019-6663 in BIG-IP
Summary
by MITRE
The BIG-IP 15.0.0-15.0.1, 14.0.0-14.1.2.2, 13.1.0-13.1.3.1, 12.1.0-12.1.5, and 11.5.1-11.6.5.1, BIG-IQ 7.0.0, 6.0.0-6.1.0, and 5.2.0-5.4.0, iWorkflow 2.3.0, and Enterprise Manager 3.1.1 configuration utility is vulnerable to Anti DNS Pinning (DNS Rebinding) attack.
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Analysis
by VulDB Data Team • 02/23/2024
The CVE-2019-6663 vulnerability represents a critical DNS rebinding attack vector affecting F5 Networks BIG-IP and related products across multiple versions. This vulnerability specifically targets the configuration utility interfaces of these systems, exposing them to man-in-the-middle attacks that can bypass standard network security controls. The flaw stems from the system's failure to properly validate DNS responses during the configuration process, creating an opportunity for attackers to manipulate network traffic and gain unauthorized access to internal systems. The vulnerability is particularly concerning because it affects widely deployed network infrastructure components that serve as critical points of control and monitoring within enterprise environments.
The technical implementation of this vulnerability involves the exploitation of DNS pinning bypass mechanisms within the affected F5 products' configuration utilities. When administrators access the web-based management interfaces, the system performs DNS resolution to determine network connectivity and service locations. Attackers can manipulate this process by hosting malicious DNS servers that initially respond with legitimate IP addresses for the target system, but then redirect to internal network addresses after the initial connection is established. This technique effectively allows attackers to bypass standard firewall and network segmentation controls that would normally prevent external access to internal systems. The vulnerability is categorized under CWE-611 (Improper Restriction of XML External Entity Reference) and aligns with ATT&CK technique T1190 (Exploit Public-Facing Application) and T1071.004 (Application Layer Protocol: DNS).
The operational impact of CVE-2019-6663 extends far beyond simple unauthorized access, as it enables attackers to perform reconnaissance, data exfiltration, and lateral movement within affected networks. Once successfully exploited, attackers can gain access to sensitive configuration data, credentials, and potentially establish persistent access points within the network infrastructure. The vulnerability affects not only the primary BIG-IP systems but also the supporting BIG-IQ, iWorkflow, and Enterprise Manager platforms, creating a broad attack surface that can compromise entire network management ecosystems. Organizations with multiple affected versions deployed across their infrastructure face significant risk of cascading security failures, as a single compromised management interface can provide attackers with visibility into interconnected systems and potentially enable further exploitation of other network components.
Mitigation strategies for CVE-2019-6663 require immediate implementation of network-level protections combined with software updates and configuration hardening measures. Organizations should implement strict DNS filtering policies that prevent resolution of internal addresses from external-facing interfaces, deploy network segmentation controls to isolate management interfaces from production networks, and establish monitoring for suspicious DNS resolution patterns. The most effective long-term solution involves applying the vendor-provided security patches that address the underlying DNS validation flaws in the affected software versions. Additionally, administrators should disable unnecessary web management interfaces, implement strong authentication mechanisms, and conduct regular security assessments to identify and remediate similar vulnerabilities in network infrastructure components. The vulnerability demonstrates the critical importance of proper input validation and network boundary protection in enterprise security architectures, particularly for systems that serve as central points of control and monitoring within complex network environments.