CVE-2022-28706 in BIG-IP
Summary
by MITRE • 05/05/2022
On F5 BIG-IP 16.1.x versions prior to 16.1.2 and 15.1.x versions prior to 15.1.5.1, when the DNS resolver configuration is used, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
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Analysis
by VulDB Data Team • 05/08/2022
The vulnerability identified as CVE-2022-28706 affects F5 BIG-IP systems running specific versions of the Traffic Management Microkernel (TMM) where DNS resolver configurations are utilized. This issue represents a denial of service condition that can be triggered by sending specially crafted DNS requests to the affected system. The vulnerability specifically impacts versions 16.1.x before 16.1.2 and 15.1.x before 15.1.5.1, making it a significant concern for organizations relying on these network infrastructure components. The flaw manifests when the TMM process terminates unexpectedly due to processing certain DNS requests that contain undisclosed or malformed parameters, leading to service disruption for legitimate network traffic.
The technical nature of this vulnerability stems from improper input validation within the DNS resolver functionality of the TMM module. When the system processes DNS queries that contain unexpected or malformed data, the internal parsing logic fails to handle these edge cases gracefully, resulting in an abrupt termination of the TMM process. This behavior aligns with CWE-248, which describes an unspecified exception being thrown without proper handling, and represents a classic example of an unhandled exception leading to system instability. The vulnerability does not appear to allow for arbitrary code execution or data disclosure, but rather focuses on system availability through process termination. The attack vector involves sending crafted DNS requests to the affected BIG-IP system, which then processes these requests through the DNS resolver configuration and triggers the termination sequence.
The operational impact of CVE-2022-28706 extends beyond simple service interruption as it can compromise the reliability of critical network infrastructure. Organizations utilizing F5 BIG-IP appliances for load balancing, application delivery, and network security may experience significant downtime when this vulnerability is exploited. The termination of the TMM process affects the entire traffic management capability of the device, potentially causing cascading failures in network services that depend on the appliance. This vulnerability can be particularly dangerous in environments where high availability and continuous operation are required, as it may lead to service degradation or complete network outages. The affected systems typically require manual intervention to restore normal operation, including restarting the TMM process or rebooting the entire appliance, which introduces additional operational overhead and potential for extended downtime.
Mitigation strategies for CVE-2022-28706 primarily focus on upgrading to the patched versions of F5 BIG-IP software, specifically versions 16.1.2 and 15.1.5.1 or later. Organizations should prioritize applying these updates through their standard change management processes while ensuring proper testing in staging environments before deployment to production systems. Network administrators should also implement monitoring solutions to detect unusual DNS request patterns that might indicate exploitation attempts, as this vulnerability can potentially be leveraged for denial of service attacks. The mitigation approach aligns with ATT&CK technique T1499.004, which covers the use of network denial of service attacks, and organizations should consider implementing network segmentation and access controls to limit exposure to potentially malicious DNS queries. Additionally, maintaining current F5 software versions and applying security patches promptly helps ensure that similar vulnerabilities are addressed before they can be exploited in operational environments.