CVE-2018-5504 in BIG-IP
Summary
by MITRE
In some circumstances, the Traffic Management Microkernel (TMM) does not properly handle certain malformed Websockets requests/responses, which allows remote attackers to cause a denial-of-service (DoS) or possible remote code execution on the F5 BIG-IP system running versions 13.0.0 - 13.1.0.3 or 12.1.0 - 12.1.3.1.
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Analysis
by VulDB Data Team • 02/22/2023
The vulnerability identified as CVE-2018-5504 affects the Traffic Management Microkernel (TMM) component of F5 BIG-IP systems, representing a critical security flaw that impacts multiple versions of the platform. This vulnerability specifically targets the handling of WebSockets requests and responses within the TMM, which serves as the core traffic management engine responsible for processing network requests and responses. The flaw exists in versions 13.0.0 through 13.1.0.3 and 12.1.0 through 12.1.3.1, making it a widespread issue across several major releases of the F5 BIG-IP platform.
The technical nature of this vulnerability stems from improper validation of malformed WebSockets requests that pass through the TMM processing pipeline. When the system encounters specially crafted malformed WebSocket frames or sequences, the TMM fails to properly handle these inputs, leading to unpredictable behavior. This improper handling can manifest as system crashes, memory corruption, or other internal processing failures that ultimately result in denial-of-service conditions. The vulnerability is particularly concerning because WebSockets represent a common and increasingly prevalent protocol used for real-time communication in web applications, making this attack vector highly relevant in modern network environments.
The operational impact of CVE-2018-5504 extends beyond simple service disruption to potentially enabling remote code execution in certain circumstances, significantly elevating the risk level. Attackers exploiting this vulnerability can remotely compromise F5 BIG-IP systems without requiring authentication, making it a prime target for automated attacks. The potential for remote code execution means that successful exploitation could allow attackers to gain full control over affected systems, potentially enabling them to establish persistent access, exfiltrate sensitive data, or use the compromised systems as launch points for further attacks within the network. This vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1059.007 for remote code execution through network services.
Organizations affected by this vulnerability should prioritize immediate remediation through official F5 security patches and updates. The mitigation strategy should include comprehensive network monitoring to detect potential exploitation attempts, implementing network segmentation to limit the impact of successful attacks, and establishing robust incident response procedures. Additionally, organizations should consider deploying Web Application Firewalls and network intrusion detection systems to help identify and block malicious WebSocket traffic patterns. The vulnerability highlights the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect critical infrastructure components. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other network components, as this vulnerability demonstrates how seemingly minor protocol handling flaws can result in catastrophic system compromise. Organizations must also ensure proper network access controls are implemented to limit exposure of F5 BIG-IP systems to untrusted networks and users.