CVE-2020-5878 in BIG-IP
Summary
by MITRE
On versions 15.1.0-15.1.0.1, 15.0.0-15.0.1.1, and 14.1.0-14.1.2.3, Traffic Management Microkernel (TMM) may restart on BIG-IP Virtual Edition (VE) while processing unusual IP traffic.
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Analysis
by VulDB Data Team • 05/01/2020
The vulnerability identified as CVE-2020-5878 affects the Traffic Management Microkernel (TMM) component of F5 BIG-IP Virtual Edition systems across specific software versions including 15.1.0 through 15.1.0.1, 15.0.0 through 15.0.1.1, and 14.1.0 through 14.1.2.3. This issue represents a significant stability concern within the network infrastructure of organizations relying on F5's BIG-IP platform for load balancing and traffic management. The vulnerability manifests when the TMM processes unusual IP traffic patterns, leading to unexpected system restarts that can result in service disruption and potential denial of service conditions. The root cause lies in the TMM's handling of malformed or atypical IP packets that trigger an internal error condition causing the microkernel to restart automatically. This behavior creates a cascading effect where legitimate traffic may be temporarily disrupted while the system recovers from the restart event.
The technical nature of this vulnerability aligns with CWE-20, which describes improper input validation, and demonstrates how insufficient validation of IP packet structures can lead to system instability. The operational impact extends beyond simple service interruption as the automatic restart process may not preserve session state or connection information, potentially affecting user experience and application availability. From an attacker's perspective, this vulnerability could be exploited to create persistent denial of service conditions by repeatedly sending malformed IP traffic that triggers the TMM restart behavior. The vulnerability operates at the network layer and affects the fundamental traffic processing capabilities of the BIG-IP system, making it particularly dangerous in environments where high availability and continuous service delivery are critical requirements. The restart mechanism suggests that the system lacks proper error handling or graceful degradation capabilities when encountering unexpected IP traffic patterns, which violates security principles that require systems to maintain operational integrity even when processing malformed inputs.
Organizations utilizing affected BIG-IP versions must implement immediate mitigations to protect their network infrastructure from potential exploitation of this vulnerability. The primary recommended action involves applying the latest security patches provided by F5 to address the underlying TMM restart condition. Network administrators should also consider implementing traffic filtering mechanisms at network boundaries to identify and block suspicious IP traffic patterns that may trigger the vulnerability. Additionally, monitoring systems should be enhanced to detect unusual restart patterns or increased error rates in TMM processes, which could serve as early warning indicators of exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1499.004, which covers network denial of service attacks, and organizations should review their incident response procedures to ensure preparedness for potential exploitation scenarios. Regular system health monitoring and maintaining updated security configurations become essential practices to prevent exploitation while the permanent fix is deployed. The vulnerability also highlights the importance of proper system hardening and input validation practices within network infrastructure components, as the issue demonstrates how insufficient validation of network traffic can lead to complete system instability and service disruption.