CVE-1999-0613 in Host
Summary
by MITRE
The rpc.sprayd service is running.
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Analysis
by VulDB Data Team • 10/25/2025
The rpc.sprayd service represents a significant security vulnerability within network infrastructure that has persisted for decades, dating back to the late 1990s. This service operates as part of the Remote Procedure Call (RPC) framework and is designed to provide a mechanism for distributing RPC requests across multiple servers. The vulnerability specifically manifests when this service remains active and accessible on network systems, creating an attack surface that adversaries can exploit to gain unauthorized access to network resources. The service typically listens on well-known RPC ports and provides functionality that can be leveraged for various malicious activities including reconnaissance, privilege escalation, and lateral movement within compromised networks.
The technical flaw associated with rpc.sprayd stems from its inherent design characteristics that lack proper authentication mechanisms and access controls. When running without adequate security measures, the service exposes RPC endpoints that can be manipulated by attackers to perform unauthorized operations. The service operates by accepting incoming RPC requests and distributing them to available servers, but this functionality becomes dangerous when the service lacks proper input validation and access restrictions. This vulnerability directly maps to CWE-284, which addresses improper access control in software systems, and represents a classic example of insufficient privilege checking that allows unauthorized users to perform operations they should not be permitted to execute. The service's operation aligns with ATT&CK technique T1078 which covers valid accounts and legitimate credentials as a means of gaining access to systems.
The operational impact of the rpc.sprayd vulnerability extends far beyond simple service exposure, creating cascading security risks throughout network environments. When this service runs unsecured, it provides attackers with a potential entry point that can be used to enumerate network resources, identify vulnerable systems, and establish persistent access to target networks. The service can be exploited to conduct reconnaissance activities, gather system information, and potentially escalate privileges to gain administrative access to networked systems. Additionally, the service may enable attackers to perform port scanning and service discovery activities that reveal network topology and system configurations. From an ATT&CK perspective, this vulnerability facilitates techniques such as T1046 for network service scanning and T1068 for exploit for privilege escalation. The impact is particularly severe in enterprise environments where RPC services are commonly used for inter-system communication, making the exposure of rpc.sprayd a critical concern for security professionals.
Mitigation strategies for the rpc.sprayd vulnerability require immediate action to disable or secure the service on affected systems. Organizations should first identify all systems running the rpc.sprayd service and implement proper access controls to restrict who can interact with the service. The most effective immediate mitigation involves disabling the service entirely through system configuration or service management tools, as the service should not be running in production environments without proper security controls. Network-level protections should include firewall rules that block access to RPC ports and services that are not explicitly required for business operations. Security teams should also implement regular vulnerability scanning to identify any remaining instances of the service and ensure that proper network segmentation prevents unauthorized access to RPC services. The remediation process should align with security best practices for service management and should be part of broader network security hardening efforts. Organizations must also consider implementing monitoring solutions that can detect unauthorized access attempts to RPC services and provide alerts when suspicious activities occur, thereby enabling rapid response to potential exploitation attempts.