CVE-2002-1712 in Windows
Summary
by MITRE
Microsoft Windows 2000 allows remote attackers to cause a denial of service (memory consumption) by sending a flood of empty TCP/IP packets with the ACK and FIN bits set to the NetBIOS port (TCP/139), as demonstrated by stream3.
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Analysis
by VulDB Data Team • 04/23/2025
This vulnerability exists in Microsoft Windows 2000 operating systems where the TCP/IP stack implementation fails to properly handle specific malformed TCP packets. The flaw manifests when the system receives a flood of TCP packets that have both the ACK and FIN control bits set simultaneously while targeting the NetBIOS port TCP/139. This particular packet construction triggers an improper state handling mechanism within the Windows kernel's network protocol implementation, causing the system to consume excessive memory resources as it attempts to process these malformed packets. The vulnerability represents a classic denial of service scenario where legitimate system resources become consumed through malicious packet flooding, ultimately leading to system instability and service unavailability.
The technical implementation of this vulnerability stems from the Windows 2000 TCP/IP stack's insufficient validation of TCP packet headers and control bit combinations. When the network layer receives packets with both ACK and FIN bits set, the system's connection state machine does not properly account for this combination, leading to memory allocation for connection tracking structures without proper cleanup. This behavior aligns with CWE-129, which addresses improper validation of input, and specifically relates to improper handling of network protocol states. The flaw demonstrates a lack of proper input sanitization and state management in the TCP/IP implementation, creating a resource exhaustion condition that can be easily exploited through automated packet flooding tools.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise system availability and stability. Attackers can leverage this weakness to consume system memory resources at a rapid rate, causing the target system to become unresponsive or crash entirely. The attack is particularly effective because it requires minimal resources to execute, making it a preferred method for attackers seeking to disrupt services without sophisticated tools. The NetBIOS port TCP/139 is commonly exposed on Windows systems, making this attack vector particularly dangerous as it can be easily discovered and exploited. This vulnerability directly impacts the availability component of the CIA triad and can be classified under the MITRE ATT&CK technique T1499.002 for network denial of service attacks, demonstrating how attackers can leverage protocol implementation weaknesses to compromise system availability.
Mitigation strategies for this vulnerability should focus on both immediate defensive measures and long-term system hardening. Network administrators should implement rate limiting and packet filtering rules at network boundaries to prevent excessive TCP packets from reaching vulnerable systems. The Windows 2000 operating system should be patched with Microsoft security updates that address the TCP/IP stack implementation flaws, though this requires careful consideration of compatibility and system stability. System monitoring should be enhanced to detect unusual memory consumption patterns and network traffic spikes that may indicate exploitation attempts. Additionally, implementing network segmentation and restricting access to TCP/139 ports from untrusted networks can significantly reduce the attack surface. The vulnerability highlights the importance of proper protocol implementation and the need for comprehensive testing of edge cases in network stack implementations to prevent resource exhaustion attacks that can be easily executed by adversaries with minimal technical expertise.