CVE-2003-0576 in IRIX
Summary
by MITRE
Unknown vulnerability in the NFS daemon (nfsd) in SGI IRIX 6.5.19f and earlier allows remote attackers to cause a denial of service (kernel panic) via certain packets that cause XDR decoding errors, a different vulnerability than CVE-2003-0619.
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Analysis
by VulDB Data Team • 06/15/2018
The vulnerability identified as CVE-2003-0576 represents a critical flaw in the Network File System (NFS) daemon implementation within SGI IRIX operating system versions 6.5.19f and earlier. This issue specifically targets the nfsd component responsible for handling NFS server operations, creating a pathway for remote attackers to disrupt system availability through carefully crafted network packets. The vulnerability operates at the kernel level where the NFS daemon processes incoming requests, making it particularly dangerous as it can lead to complete system shutdowns.
The technical root cause of this vulnerability lies in the XDR (External Data Representation) decoding mechanism within the NFS daemon implementation. XDR is a standard data serialization format used in network protocols to ensure data can be correctly interpreted across different machine architectures. When the nfsd daemon receives malformed or specially constructed packets that trigger XDR decoding errors, the kernel becomes unable to properly handle these malformed data structures, resulting in a kernel panic condition. This represents a classic buffer over-read or improper input validation flaw where the system fails to gracefully handle unexpected data formats.
From an operational perspective, this vulnerability poses significant risk to systems running SGI IRIX 6.5.19f and earlier versions, particularly those serving as NFS servers in networked environments. Remote attackers can exploit this weakness without requiring authentication, making it an attractive target for denial of service attacks that can render entire file services unavailable. The kernel panic resulting from exploitation typically requires system reboot to restore normal operation, causing service disruption that can impact multiple users and applications depending on the NFS shares. Organizations relying on IRIX systems for critical file services face potential business disruption and data accessibility issues.
The vulnerability aligns with CWE-129, which addresses improper input validation, and relates to the broader category of kernel-level buffer overflow conditions that can lead to system crashes. From an ATT&CK framework perspective, this represents a privilege escalation and denial of service technique under the T1499 category of Network Denial of Service, with potential for lateral movement if the compromised system serves as a gateway to other network resources. Mitigation strategies should include immediate patching of the affected IRIX versions to the latest available security updates from SGI, network segmentation to limit exposure, and implementation of intrusion detection systems to monitor for suspicious NFS traffic patterns. Additionally, administrators should consider implementing network access controls that restrict NFS service exposure to trusted networks only, as the vulnerability can be exploited from any remote location with network connectivity to the affected system.