CVE-2005-1184 in Windows
Summary
by MITRE
The TCP/IP stack in multiple operating systems allows remote attackers to cause a denial of service (CPU consumption) via a TCP packet with the correct sequence number but the wrong Acknowledgement number, which generates a large number of "keep alive" packets. NOTE: some followups indicate that this issue could not be replicated.
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Analysis
by VulDB Data Team • 01/22/2025
The vulnerability described in CVE-2005-1184 represents a significant denial of service weakness within the Transmission Control Protocol implementation across multiple operating systems. This flaw exploits the fundamental mechanisms of TCP communication protocols where attackers can manipulate packet sequence and acknowledgment numbers to trigger excessive system resource consumption. The vulnerability specifically targets the TCP stack's handling of packets that contain correct sequence numbers but incorrect acknowledgment numbers, creating a condition that forces the system to maintain unnecessary connections and generate continuous keep-alive traffic.
The technical mechanism behind this vulnerability operates through the TCP protocol's connection state management and acknowledgment processing. When a TCP stack receives a packet with a valid sequence number but an incorrect acknowledgment number, it triggers a specific response behavior that causes the system to continuously send keep-alive packets to maintain connection state. This behavior stems from the protocol's requirement to verify connection integrity and handle out-of-order packets, but the implementation flaw allows attackers to exploit this verification process to create a resource exhaustion condition. The vulnerability is classified under CWE-129 as an improper input validation, specifically related to incorrect handling of TCP packet parameters during connection establishment and maintenance phases.
The operational impact of this vulnerability manifests as significant CPU consumption and system resource depletion, effectively creating a denial of service condition that can render affected systems unusable. Attackers can exploit this weakness by sending a carefully crafted TCP packet that triggers the keep-alive response mechanism repeatedly, causing the target system to consume substantial processing power and memory resources. The vulnerability affects multiple operating systems, indicating a widespread implementation issue within TCP stack implementations that goes beyond individual vendor-specific code. This cross-platform nature makes the vulnerability particularly dangerous as it can be exploited against various network infrastructure components and end-user systems without requiring specific knowledge of the underlying operating system.
The exploitation of this vulnerability requires minimal technical expertise and can be performed remotely, making it a particularly attractive attack vector for malicious actors seeking to disrupt network services. The attack does not require authentication or specific privileges, and can be executed against any system running an affected TCP implementation. The referenced followups indicating that the issue could not be replicated suggest either that the vulnerability was difficult to reproduce in certain environments or that the specific conditions required for exploitation were not commonly met in real-world deployments. However, the potential for resource exhaustion through TCP packet manipulation remains a valid concern in network security and aligns with ATT&CK technique T1498 for resource exhaustion attacks. Organizations should implement proper TCP stack configuration and monitoring to detect unusual packet patterns and prevent exploitation of this class of vulnerabilities.