CVE-2005-0139 in IRIX
Summary
by MITRE
Unknown vulnerability in rpc.mountd in SGI IRIX 6.5.25, 6.5.26, and 6.5.27 does not sufficiently restrict access rights for read-mostly exports, which allows attackers to conduct unauthorized activities.
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Analysis
by VulDB Data Team • 04/11/2019
The vulnerability identified as CVE-2005-0139 affects the rpc.mountd service in SGI IRIX operating system versions 6.5.25 through 6.5.27. This issue resides within the Network File System (NFS) implementation where the rpc.mountd daemon fails to properly enforce access controls for read-mostly exported filesystems. The flaw represents a critical security weakness in the NFS export management system that has persisted across multiple patch levels of the IRIX 6.5.x release series, indicating a fundamental design or implementation issue that was not adequately addressed in the security controls.
The technical nature of this vulnerability stems from insufficient validation and access restriction mechanisms within the rpc.mountd service when processing mount requests for filesystem exports. Specifically, the service does not properly validate client access rights when handling read-mostly export configurations, allowing unauthorized users to potentially gain elevated privileges or access restricted filesystem content. This type of vulnerability falls under the category of improper access control as defined by CWE-284, where the system fails to properly enforce authorization mechanisms for resource access. The flaw essentially allows attackers to bypass normal access controls that should prevent unauthorized read operations on exported filesystems.
The operational impact of this vulnerability is significant as it enables attackers to conduct unauthorized activities against systems running affected IRIX versions. An attacker could potentially exploit this weakness to access sensitive data, modify filesystem content, or establish persistent access to the system through the compromised NFS export mechanisms. This vulnerability particularly affects enterprise environments where IRIX systems may be running legacy NFS services for file sharing or data access. The attack surface extends beyond simple data theft to include potential privilege escalation scenarios that could lead to complete system compromise. According to ATT&CK framework, this vulnerability maps to T1078 for valid accounts and T1046 for network service scanning, as attackers would need to identify the vulnerable NFS service and potentially exploit it to gain unauthorized access.
Mitigation strategies for this vulnerability should include immediate patching of affected IRIX systems to the latest available security updates from SGI. Organizations should also implement network segmentation to restrict access to NFS services, disable unnecessary NFS exports, and enforce strict firewall rules that limit access to rpc.mountd and related NFS services. Additionally, monitoring for unusual mount activity and implementing intrusion detection systems can help identify potential exploitation attempts. The vulnerability demonstrates the importance of proper access control implementation in network services and highlights the risks associated with legacy operating systems that may not receive ongoing security support. Organizations should consider migrating away from unsupported platforms to ensure continued security coverage and access to security updates.