CVE-2002-1201 in AIX
Summary
by MITRE
IBM AIX 4.3.3 and AIX 5 allows remote attackers to cause a denial of service (CPU consumption or crash) via a flood of malformed TCP packets without any flags set, which prevents AIX from releasing the associated memory buffers.
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Analysis
by VulDB Data Team • 10/27/2024
This vulnerability exists in IBM AIX operating systems version 4.3.3 and 5.0, where remote attackers can exploit a flaw in the TCP protocol implementation to cause denial of service conditions. The vulnerability specifically targets the handling of TCP packets that lack any flags set in their header structure. When the AIX system receives such malformed packets, it fails to properly release associated memory buffers, leading to resource exhaustion that can result in either sustained high cpu utilization or complete system crashes. The flaw stems from inadequate input validation and memory management within the TCP stack implementation, where the system does not properly handle edge cases in packet processing. This vulnerability directly relates to CWE-129, which addresses improper validation of input boundaries, and CWE-400, which covers resource exhaustion vulnerabilities. From an operational perspective, this vulnerability presents a significant risk to network availability as attackers can consume system resources without requiring authentication or privileged access. The attack vector is particularly concerning because it requires only network access and can be executed from remote locations, making it a low-effort, high-impact threat. The vulnerability can be classified under ATT&CK technique T1498, which covers network denial of service attacks, and T1595, which involves network infiltration through protocol manipulation. Organizations running affected AIX versions face potential system downtime and service disruption, as the memory buffer exhaustion can gradually degrade system performance until complete failure occurs. The impact extends beyond simple service interruption to potentially affecting business continuity and operational availability. The root cause of this vulnerability lies in the TCP implementation's failure to properly validate packet headers and manage memory allocation for malformed traffic. When processing TCP packets with no flags set, the system allocates memory buffers to handle the packet processing but fails to release these resources upon encountering the malformed input, creating a memory leak scenario that progressively consumes available system resources. This behavior demonstrates poor defensive programming practices and inadequate error handling mechanisms within the network stack. The vulnerability is particularly dangerous because it can be exploited using simple flooding techniques, where an attacker sends a large volume of malformed packets to overwhelm the system's memory management capabilities. The attack requires minimal sophistication and can be automated, making it a preferred method for conducting denial of service attacks against vulnerable systems. Network administrators should consider implementing network segmentation and access control measures to limit exposure, while also monitoring for unusual traffic patterns that may indicate exploitation attempts. The vulnerability highlights the importance of robust input validation and proper resource management in network protocol implementations. Organizations should prioritize applying vendor patches and updates to address this issue, as the affected systems lack proper safeguards against malformed packet processing. Additionally, implementing intrusion detection systems and network monitoring tools can help detect and mitigate exploitation attempts before they cause significant damage to system availability. The vulnerability represents a classic example of how protocol implementation flaws can be exploited to cause resource exhaustion, demonstrating the critical need for comprehensive security testing and validation of network stack components. This type of vulnerability underscores the importance of following secure coding practices and maintaining up-to-date system configurations to prevent exploitation of fundamental protocol implementation weaknesses.