CVE-2000-1089 in PhoneBook Server
Summary
by MITRE
Buffer overflow in Microsoft Phone Book Service allows local users to execute arbitrary commands, aka the "Phone Book Service Buffer Overflow" vulnerability.
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Analysis
by VulDB Data Team • 10/11/2025
The CVE-2000-1089 vulnerability represents a critical buffer overflow flaw within Microsoft Phone Book Service that enables local attackers to execute arbitrary code on affected systems. This vulnerability specifically targets the phone book service component that manages contact information and dialing configurations within Microsoft Windows environments. The flaw arises from insufficient input validation and boundary checking within the service's memory management routines, creating opportunities for malicious code injection through crafted buffer inputs.
This buffer overflow vulnerability operates at the kernel level within the Windows operating system, making it particularly dangerous as it can be exploited by local users who already have system access. The vulnerability falls under CWE-121, which classifies buffer overflow conditions where insufficient boundary checks allow data to overwrite adjacent memory locations. The attack vector involves local privilege escalation through a maliciously crafted phone book entry or service configuration that triggers the overflow condition when processed by the vulnerable service.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with potential access to sensitive system resources and data. Local users who can interact with the phone book service can leverage this flaw to gain elevated privileges, execute malicious code with system-level permissions, and potentially establish persistent access to the compromised system. The vulnerability affects multiple versions of Windows 2000 and Windows NT systems where the phone book service remains enabled and accessible.
From an attack perspective, this vulnerability aligns with ATT&CK technique T1068 which covers local privilege escalation through exploitation of system services. The attack requires minimal privileges to initiate and can be automated once the attacker identifies the vulnerable service configuration. The exploit typically involves crafting a specific input that exceeds the allocated buffer size, causing memory corruption that allows execution of arbitrary code. This makes the vulnerability particularly concerning in enterprise environments where multiple users may have local access to systems running vulnerable phone book services.
Mitigation strategies for CVE-2000-1089 should focus on immediate patch deployment through Microsoft security updates, service configuration hardening, and access control restrictions. System administrators should disable unnecessary phone book service components and implement proper input validation procedures to prevent buffer overflow conditions. The vulnerability demonstrates the importance of proper memory management and boundary checking in system services, emphasizing the need for regular security assessments and vulnerability management programs. Organizations should also implement network segmentation and privilege separation to limit the potential impact of such local privilege escalation vulnerabilities.