CVE-1999-0228 in Windows
Summary
by MITRE
denial of service in rpcss.exe program (rpc locator) in windows nt.
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Analysis
by VulDB Data Team • 04/16/2026
The vulnerability identified as CVE-1999-0228 represents a critical denial of service condition affecting the rpcss.exe process within Microsoft Windows NT operating systems. This issue specifically targets the Remote Procedure Call (RPC) Locator service which serves as a fundamental component for distributed computing operations in the windows environment. The rpcss.exe program acts as the RPC endpoint mapper and locator service that enables applications to discover and communicate with RPC servers across network boundaries. When exploited, this vulnerability allows malicious actors to disrupt the normal operation of the RPC service, effectively rendering critical system functionality unavailable to legitimate users and administrators.
The technical flaw manifests through improper handling of certain RPC requests within the rpcss.exe process, where the service fails to properly validate incoming requests or manage resource allocation during processing. This weakness creates a condition where malformed or specially crafted RPC messages can cause the rpcss.exe service to crash or become unresponsive, leading to a complete denial of service for all RPC-based services that depend on this locator mechanism. The vulnerability specifically affects Windows NT 4.0 and earlier versions where the RPC service implementation contained insufficient input validation and error handling mechanisms. The flaw operates at the system level where the service process does not adequately protect against malformed data structures or excessive resource consumption patterns that could be exploited through network-based attacks.
The operational impact of this vulnerability extends beyond simple service disruption as it affects the fundamental infrastructure upon which many enterprise applications depend. When the rpcss.exe service becomes unavailable, all RPC-based services including file sharing, print services, and various system management functions become inaccessible, potentially compromising entire network operations. This vulnerability particularly affects organizations relying on Windows NT servers for critical business operations, as the disruption can cascade through dependent services and applications that utilize RPC for inter-process communication. The attack vector typically involves sending specially crafted RPC requests to the target system, which when processed by the vulnerable rpcss.exe service, trigger the service crash or resource exhaustion that leads to the denial of service condition.
Mitigation strategies for this vulnerability require immediate implementation of security patches provided by Microsoft as part of their regular security updates for Windows NT systems. Organizations should ensure that all Windows NT servers are updated with the appropriate service packs and security fixes that address the RPC service vulnerabilities. Network-level protections including firewall rules that limit RPC port access and implementation of intrusion detection systems can help reduce the attack surface for this vulnerability. Additionally, administrators should implement proper monitoring of rpcss.exe service status and establish alerting mechanisms to detect unusual service behavior or frequent restarts that may indicate exploitation attempts. The vulnerability aligns with CWE-20, representing a weakness in input validation, and maps to ATT&CK technique T1499.004 related to network disruption through service interruption, making it a significant concern for enterprise security posture management and compliance with industry standards for system hardening and vulnerability remediation.