CVE-2003-0176 in IRIX
Summary
by MITRE
The Name Service Daemon (nsd), when running on an NIS master on SGI IRIX 6.5.x through 6.5.20f, and possibly earlier versions, allows remote attackers to cause a denial of service (crash) via a UDP port scan.
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Analysis
by VulDB Data Team • 04/11/2019
The vulnerability identified as CVE-2003-0176 affects the Name Service Daemon (nsd) component within the Network Information Service (NIS) infrastructure on SGI IRIX operating systems. This flaw manifests specifically when nsd operates on an NIS master server running IRIX versions 6.5.x through 6.5.20f, creating a potential vector for remote attackers to disrupt system availability. The issue stems from insufficient input validation and error handling within the nsd service when processing network traffic, particularly UDP packets that form part of standard port scanning activities.
The technical exploitation of this vulnerability occurs through a UDP port scan initiated by remote attackers against the nsd service. When the daemon receives malformed or specially crafted UDP packets during such scans, it fails to properly validate the incoming data structures, leading to an unhandled exception that causes the service to crash and terminate unexpectedly. This behavior represents a classic buffer overflow or improper input validation flaw that can be leveraged to achieve a denial of service condition. The vulnerability falls under the CWE-125 weakness category, which encompasses out-of-bounds read errors, though the specific manifestation here involves improper state handling during network packet processing. From an attack perspective, this vulnerability maps to the ATT&CK technique T1499.004, specifically targeting network denial of service through service interruption.
The operational impact of this vulnerability extends beyond simple service disruption, as it affects the core network naming infrastructure that many applications and system services depend upon for hostname resolution and user authentication. When the nsd daemon crashes, it can cause cascading failures throughout the NIS domain, potentially affecting multiple system services that rely on NIS for user and host information. The crash typically results in complete service unavailability until manual intervention occurs to restart the daemon, which may also require restarting dependent services. This vulnerability is particularly concerning in enterprise environments where NIS serves as a critical infrastructure component for managing user accounts, hostnames, and network services across multiple systems. The exploitation requires minimal technical expertise and can be accomplished through standard network scanning tools, making it a significant risk for systems that are not properly patched or isolated from untrusted networks.
Mitigation strategies for this vulnerability should include immediate patching of affected IRIX systems with the vendor-provided security updates, which would address the underlying input validation flaws in the nsd daemon. Network segmentation and access control measures should be implemented to restrict UDP traffic to the affected service, particularly on port 111 which is commonly used by NIS services. Additionally, implementing network monitoring and intrusion detection systems can help identify and alert on suspicious port scanning activities that may attempt to exploit this vulnerability. The recommended approach aligns with the NIST cybersecurity framework's configuration management and vulnerability management practices, ensuring that systems maintain a secure baseline configuration. Organizations should also consider implementing redundant naming services or migrating away from NIS where possible, as this vulnerability highlights the inherent security limitations of older network services that lack modern security features such as proper input sanitization and robust error handling mechanisms.