CVE-2017-6158 in BIG-IP
Summary
by MITRE
In F5 BIG-IP 12.0.0-12.1.2, 11.6.0-11.6.1, 11.5.1-11.5.5, or 11.2.1 there is a vulnerability in TMM related to handling of invalid IP addresses.
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Analysis
by VulDB Data Team • 02/28/2023
The vulnerability identified as CVE-2017-6158 affects F5 BIG-IP appliances across multiple versions including 12.0.0 through 12.1.2, 11.6.0 through 11.6.1, 11.5.1 through 11.5.5, and 11.2.1. This issue resides within the Traffic Management Microkernel TMM component which serves as the core processing engine for traffic handling in F5's BIG-IP platform. The flaw manifests when the TMM encounters invalid IP addresses during packet processing, creating a potential for system instability and denial of service conditions. The vulnerability stems from insufficient validation mechanisms within the TMM's IP address handling routines, allowing malformed or unexpected IP address formats to trigger unexpected behavior in the system's packet processing pipeline.
The technical nature of this vulnerability involves a buffer over-read condition that occurs when the TMM attempts to process invalid IP addresses without proper input sanitization. This type of flaw falls under CWE-125 which describes out-of-bounds read vulnerabilities, where an application reads data beyond the boundaries of a buffer. When malformed IP addresses are processed, the TMM's parsing logic fails to properly validate the address structure, leading to memory access violations that can cause the TMM process to crash or become unresponsive. The vulnerability is particularly concerning because it operates at the kernel level within the TMM, meaning that exploitation can result in complete system instability affecting all network services managed by the BIG-IP appliance.
The operational impact of CVE-2017-6158 extends beyond simple denial of service conditions to potentially compromise the entire network infrastructure managed by the affected F5 appliance. Attackers can leverage this vulnerability to disrupt critical network services, causing cascading failures that affect business operations and customer connectivity. The vulnerability is particularly dangerous in environments where F5 BIG-IP appliances serve as primary load balancers, firewalls, or application delivery controllers, as these devices often form the backbone of enterprise network security and traffic management. The attack surface is broad since any network traffic passing through the vulnerable appliance could potentially trigger the vulnerability, making it difficult to predict and prevent attacks.
From a cybersecurity perspective, this vulnerability aligns with tactics described in the MITRE ATT&CK framework under the T1499 category for Network Denial of Service, where adversaries seek to disrupt network services through system instability. The vulnerability can be exploited through various attack vectors including malformed packets, spoofed addresses, or crafted network traffic that specifically targets the TMM's IP address parsing logic. Organizations should implement immediate mitigation strategies including applying the vendor-provided security patches, implementing network segmentation to limit exposure, and deploying intrusion detection systems that can identify anomalous traffic patterns associated with exploitation attempts. The vulnerability also highlights the importance of robust input validation practices and the need for comprehensive security testing of core network components that handle untrusted data inputs, as outlined in the OWASP Top Ten security principles and industry best practices for secure software development.