CVE-2002-2117 in Windows
Summary
by MITRE
Microsoft Windows XP allows remote attackers to cause a denial of service (CPU consumption) by flooding UDP port 500 (ISAKMP).
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Analysis
by VulDB Data Team • 07/09/2024
The vulnerability described in CVE-2002-2117 represents a significant denial of service weakness in Microsoft Windows XP operating systems that specifically targets the Internet Security Association and Key Management Protocol implementation. This flaw manifests when the system receives a large volume of malformed or excessive UDP traffic directed at port 500, which is the standard port for ISAKMP (Internet Security Association and Key Management Protocol) communications. The vulnerability stems from inadequate input validation and resource management within the Windows XP kernel's handling of ISAKMP packets, creating a condition where legitimate system resources become consumed in processing these malicious packets. The attack vector is particularly concerning as it requires no authentication or privileged access, allowing remote attackers to exploit the weakness from any network location.
The technical implementation of this vulnerability involves the exploitation of a fundamental flaw in how Windows XP processes incoming ISAKMP messages through the UDP protocol. When the system receives UDP packets on port 500, it attempts to parse and validate the ISAKMP headers and associated data structures without proper bounds checking or resource allocation limits. This processing behavior creates a scenario where an attacker can flood the system with specially crafted packets that trigger excessive CPU utilization as the operating system attempts to handle malformed or oversized ISAKMP messages. The vulnerability is categorized under CWE-129 as an insufficient input validation issue, specifically involving improper handling of input data that leads to resource exhaustion. The flaw represents a classic example of a resource exhaustion attack that consumes system processing power without causing system crashes, instead leading to performance degradation and service unavailability.
The operational impact of this vulnerability extends beyond simple service disruption to create significant business continuity concerns for organizations running Windows XP systems. When exploited, the attack causes sustained high CPU utilization that can render the affected system effectively unusable for legitimate users while maintaining network connectivity. The vulnerability affects systems that have ISAKMP services enabled or that are configured to accept ISAKMP traffic, which includes many network infrastructure devices and security appliances that rely on IPsec protocols. Organizations with Windows XP systems that are part of larger network infrastructures may find that a single compromised host can cause cascading effects throughout their network, as the CPU exhaustion affects not only the targeted system but can also impact network performance and availability for other connected services. This vulnerability aligns with ATT&CK technique T1499.001 for resource exhaustion and demonstrates how attackers can leverage protocol implementation weaknesses to achieve persistent denial of service conditions.
Mitigation strategies for this vulnerability require a multi-layered approach that combines network-level protections with system-level hardening measures. Organizations should implement firewall rules that restrict access to UDP port 500 from untrusted networks, effectively blocking the attack vector while maintaining necessary security functions. Network administrators should also consider disabling ISAKMP services on systems that do not require IPsec functionality, reducing the attack surface for this specific vulnerability. Additionally, implementing rate limiting and traffic shaping mechanisms at network boundaries can help prevent the exploitation by limiting the volume of UDP packets that can be processed by affected systems. System-level mitigations include applying Microsoft security patches and updates that address the underlying protocol handling issues, as well as configuring system monitoring to detect unusual CPU utilization patterns that may indicate exploitation attempts. The vulnerability also underscores the importance of maintaining up-to-date security practices and demonstrates why organizations should prioritize migration from legacy systems like Windows XP to more modern operating systems with enhanced security features and better vulnerability management capabilities.