CVE-2007-1529 in Windows
Summary
by MITRE
The LLTD Responder in Microsoft Windows Vista does not send the Mapper a response to a DISCOVERY packet if another host has sent a spoofed response first, which allows remote attackers to spoof arbitrary hosts via a network-based race condition, aka the "Total Spoof" attack.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 09/17/2018
The vulnerability described in CVE-2007-1529 represents a critical flaw in the Link Layer Topology Discovery (LLTD) Responder component of Microsoft Windows Vista operating systems. This issue stems from a race condition in the network discovery protocol implementation that enables malicious actors to perform sophisticated host spoofing attacks. The LLTD protocol is designed to help devices discover and identify network topology information, including the presence of other devices and their capabilities, which is essential for network management and device connectivity. However, the implementation contains a fundamental design flaw that creates an exploitable timing window in the response handling mechanism.
The technical flaw manifests when multiple hosts attempt to respond to the same LLTD DISCOVERY packet within a very short time frame. The Windows Vista LLTD Responder, which is responsible for responding to these discovery requests, fails to properly handle cases where a spoofed response arrives before the legitimate one. When this race condition occurs, the responder becomes confused and does not send its own response to the Mapper component, effectively allowing the attacker to maintain control over the network discovery process. This behavior violates the fundamental principle of network protocol design where legitimate responses should always be prioritized over spoofed ones, creating a scenario where an attacker can completely hijack the discovery process without detection.
The operational impact of this vulnerability extends beyond simple network disruption to encompass significant security implications for enterprise environments. Attackers can leverage this weakness to perform man-in-the-middle attacks, create false network topologies, and potentially gain unauthorized access to network resources by impersonating legitimate devices. The attack is particularly dangerous because it operates at the network layer without requiring authentication or elevated privileges, making it accessible to any attacker with network access. The vulnerability affects not just individual systems but entire network infrastructures that rely on LLTD for device discovery and management, potentially allowing attackers to map network topologies, identify vulnerable devices, and establish persistent access points. This weakness directly aligns with attack patterns documented in the ATT&CK framework under the Network Discovery and Credential Access tactics, where adversaries exploit protocol implementation flaws to gain deeper network visibility and control.
Mitigation strategies for this vulnerability require a multi-layered approach that addresses both the immediate protocol-level issue and broader network security practices. Organizations should implement network segmentation and access control measures to limit the impact of such attacks, while also deploying network monitoring solutions that can detect anomalous LLTD traffic patterns. Microsoft released patches for this vulnerability, but the underlying design flaw highlights the importance of proper race condition handling in network protocols. Security professionals should consider disabling LLTD functionality on network segments where the risk is high, particularly in environments with untrusted network access. The vulnerability also underscores the need for comprehensive protocol security testing and adherence to security standards such as those defined in the Common Weakness Enumeration (CWE) catalog, specifically CWE-362 which addresses race conditions. Organizations must also ensure that network discovery protocols are properly configured with appropriate access controls and that network administrators regularly audit discovery service configurations to prevent exploitation of similar timing-based vulnerabilities.