CVE-2017-6132 in BIG-IP
Summary
by MITRE
In F5 BIG-IP LTM, AAM, AFM, Analytics, APM, ASM, DNS, GTM, Link Controller, PEM and Websafe software version 13.0.0, 12.0.0 to 12.1.2, 11.6.0 to 11.6.1 and 11.5.0 - 11.5.4, an undisclosed sequence of packets sent to BIG-IP High Availability state mirror listeners (primary and/or secondary IP) may cause TMM to restart.
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Analysis
by VulDB Data Team • 01/18/2023
The vulnerability identified as CVE-2017-6132 affects F5 BIG-IP systems across multiple modules including Local Traffic Manager AAM AFM Analytics APM ASM DNS GTM Link Controller PEM and Websafe with specific versions ranging from 13.0.0 through 12.1.2 11.6.1 and 11.5.4. This issue represents a critical reliability concern within the high availability configuration of F5 appliances where the system's ability to maintain continuous operation becomes compromised through seemingly innocuous network traffic patterns. The vulnerability specifically targets the TMM or Traffic Management Module which serves as the core processing unit responsible for handling network traffic and maintaining service availability in high-availability configurations.
The technical flaw manifests when an undisclosed sequence of packets is transmitted to the BIG-IP High Availability state mirror listeners which operate on both primary and secondary IP addresses within the failover configuration. This particular packet sequence triggers an unexpected behavior within the TMM process causing it to restart automatically without proper shutdown procedures. The restart event occurs at the system level where the TMM module undergoes a complete termination and reinitialization cycle which interrupts ongoing network connections and service availability. This vulnerability operates at the network protocol level where malformed or specially crafted packet sequences can exploit memory management or state handling mechanisms within the BIG-IP software stack.
The operational impact of this vulnerability extends beyond simple service disruption as it affects the fundamental high availability guarantees that organizations rely upon when deploying F5 BIG-IP solutions. When TMM restarts due to this vulnerability, it creates a cascading effect where the system transitions through failover procedures potentially resulting in service degradation or complete outages. The timing of the restart can occur at any point during active network operations making it particularly dangerous for production environments where continuous availability is critical. Network administrators may experience unexpected downtime while the system attempts to recover from the restart event, and the automatic failover mechanisms may be triggered unnecessarily, leading to resource consumption and potential performance degradation.
Organizations affected by CVE-2017-6132 should implement immediate mitigation strategies including network segmentation to restrict access to the high availability mirror listeners, deployment of network access control lists to filter suspicious packet sequences, and monitoring for unusual traffic patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-691 Uncontrolled Resource Consumption which describes situations where insufficient resource management allows attackers to cause denial of service through resource exhaustion or system instability. From an ATT&CK perspective this vulnerability maps to T1499.004 Network Denial of Service and T1499.001 Endpoint Denial of Service where the attacker leverages system instability to cause service disruption. The recommended mitigation approach includes applying the vendor-provided security patches and updates, implementing network monitoring solutions to detect anomalous packet sequences, and establishing incident response procedures to handle unexpected system restarts. Additionally organizations should consider temporary network isolation of the affected high availability listeners until comprehensive patching can be implemented across all affected systems in the environment.