CVE-2007-1530 in Windows
Summary
by MITRE
The LLTD Mapper in Microsoft Windows Vista does not properly gather responses to EMIT packets, which allows remote attackers to cause a denial of service (mapping failure) by omitting an ACK response, which triggers an XML syntax error.
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Analysis
by VulDB Data Team • 09/17/2018
The vulnerability described in CVE-2007-1530 resides within the Link-Layer Topology Discovery (LLTD) Mapper component of Microsoft Windows Vista operating systems. This flaw specifically affects the LLTD protocol implementation that enables network devices to discover and map their topology within local networks. The LLTD protocol operates through a series of EMIT and ACK packets exchanged between devices to establish network mappings and maintain topology awareness. The vulnerability manifests when the LLTD Mapper fails to properly process responses to EMIT packets, creating a condition where remote attackers can exploit the protocol's response handling mechanism.
The technical exploitation of this vulnerability occurs through manipulation of the acknowledgment response behavior within the LLTD protocol. When an attacker sends an EMIT packet to a Windows Vista system and deliberately omits the expected ACK response, the LLTD Mapper component becomes unable to properly parse the incomplete packet sequence. This failure triggers an XML syntax error within the underlying parsing mechanism, causing the LLTD service to malfunction and ultimately leading to a denial of service condition. The vulnerability stems from insufficient input validation and error handling within the XML parser used by the LLTD Mapper, which does not properly account for malformed or incomplete packet responses.
From an operational perspective, this vulnerability presents a significant risk to network availability and service integrity within Windows Vista environments. The denial of service impact affects the LLTD discovery functionality, which is critical for network management and device identification within local networks. Network administrators may experience disruptions in network topology discovery, device mapping, and related network management services. The vulnerability can be exploited remotely without requiring authentication, making it particularly dangerous in unsecured network environments where attackers can easily target vulnerable systems. This weakness directly impacts the availability aspect of the CIA triad and can be classified under CWE-20 as "Improper Input Validation" and CWE-119 as "Improper Access to Resources" within the Common Weakness Enumeration framework.
The attack vector for this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1499 category for "Endpoint Denial of Service" and T1071 for "Application Layer Protocol" as it exploits a specific network protocol implementation. The exploitation requires minimal privileges and can be automated, making it attractive to attackers seeking to disrupt network services. Organizations running Windows Vista systems are particularly vulnerable since this was a widespread implementation issue affecting the operating system's core network discovery capabilities. The vulnerability demonstrates a classic example of how protocol-level implementation flaws can be leveraged for denial of service attacks, highlighting the importance of robust error handling and input validation in network services.
Mitigation strategies for CVE-2007-1530 should focus on both immediate defensive measures and long-term architectural improvements. Microsoft released a security update that addressed the XML parsing vulnerability within the LLTD Mapper component, which should be deployed immediately across all affected Windows Vista systems. Network administrators should also consider disabling LLTD functionality on systems where it is not required, particularly in environments where the service is not essential for network management operations. Additional defensive measures include implementing network segmentation to limit exposure of vulnerable systems and monitoring network traffic for unusual EMIT packet patterns that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper input validation and error handling in network protocol implementations, particularly those that operate at the link layer where timing and response behaviors are crucial for service availability. Organizations should also review their network discovery protocols and consider alternative discovery mechanisms that do not rely on vulnerable implementations like LLTD.