CVE-2001-0237 in Windows
Summary
by MITRE
Memory leak in Microsoft 2000 domain controller allows remote attackers to cause a denial of service by repeatedly connecting to the Kerberos service and then disconnecting without sending any data.
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Analysis
by VulDB Data Team • 05/08/2019
The vulnerability described in CVE-2001-0237 represents a critical memory management flaw within Microsoft Windows 2000 domain controllers that operates at the Kerberos authentication service level. This issue stems from improper handling of network connections within the Kerberos protocol implementation, specifically when clients establish connections to the domain controller's Kerberos service without transmitting any authentication data. The flaw manifests as a progressive memory consumption pattern where each disconnected connection consumes a portion of the system's available memory without proper cleanup, ultimately leading to system instability and service disruption. The vulnerability operates at the network protocol level, leveraging the authentication mechanisms that are fundamental to domain controller operations and enterprise network security infrastructure.
The technical root cause of this memory leak resides in the Kerberos service implementation within the Windows 2000 domain controller operating system. When remote clients connect to the Kerberos service port and immediately disconnect without sending authentication requests, the domain controller fails to properly release allocated memory resources associated with these connection sessions. This represents a classic memory management error where allocated memory blocks are not properly deallocated during the connection lifecycle, creating a resource exhaustion condition over time. The flaw specifically affects the service principal name (SPN) and ticket granting service components of the Kerberos protocol stack, where connection state information persists in memory even after the client has terminated the session. This behavior violates fundamental resource management principles and creates a predictable pattern of memory consumption that can be exploited by malicious actors.
The operational impact of CVE-2001-0237 extends beyond simple denial of service conditions to potentially compromise entire domain controller operations and enterprise network availability. When exploited continuously, the memory leak can cause the domain controller to consume all available system memory, resulting in system crashes, application failures, and complete service unavailability for legitimate users. This vulnerability particularly affects enterprise environments where domain controllers serve as critical infrastructure components for authentication and authorization services. The impact is exacerbated in high-traffic environments where multiple concurrent connection attempts can rapidly deplete system resources. Network administrators may observe gradual performance degradation before complete service failure, making this vulnerability particularly dangerous as it can go unnoticed until significant damage occurs. The flaw essentially creates a resource starvation condition that undermines the fundamental security and availability properties that domain controllers must maintain.
Mitigation strategies for this vulnerability require both immediate patching and operational security measures to address the underlying memory management flaw. Microsoft released a security update that corrected the memory leak in the Kerberos service implementation, which should be deployed immediately across all affected Windows 2000 domain controllers. Network administrators should implement connection rate limiting and monitoring to detect unusual connection patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-401, which specifically addresses memory leaks in software implementations, and represents a classic example of improper resource management that violates the principle of resource cleanup. From an ATT&CK framework perspective, this vulnerability maps to the privilege escalation and denial of service tactics, as it allows attackers to consume system resources and potentially gain unauthorized access to domain controller functions. Organizations should also implement network segmentation and access controls to limit exposure of domain controllers to untrusted networks while maintaining proper monitoring of authentication service availability and resource utilization metrics.