CVE-2009-1954 in AIX
Summary
by MITRE
Unspecified vulnerability in portmapper (aka portmap) in IBM AIX 5.3 allows attackers to cause a denial of service (daemon hang) via unknown vectors, related to libtli.
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Analysis
by VulDB Data Team • 04/11/2019
The vulnerability identified as CVE-2009-1954 resides within the portmapper service, also known as portmap, which is a critical component in IBM AIX 5.3 operating systems. This service functions as a daemon that maps RPC (Remote Procedure Call) program numbers to transport layer addresses, enabling distributed applications to locate and communicate with RPC services across network boundaries. The portmapper operates as a foundational element in the RPC infrastructure, making it a prime target for attackers seeking to disrupt system operations. The vulnerability specifically affects the libtli library component, which provides the transport layer interface for network communications and is integral to the portmapper's functionality.
The technical flaw manifests as an unspecified weakness within the portmapper daemon that can be exploited to trigger a denial of service condition resulting in daemon hang. This occurs when attackers leverage unknown vectors that cause the portmapper process to become unresponsive or enter an infinite loop, effectively preventing legitimate users from accessing RPC services that depend on this mapping functionality. The libtli library component appears to be particularly susceptible to malformed input or specific network traffic patterns that cause the daemon to malfunction. The vulnerability's classification as unspecified suggests that the exact nature of the attack vectors or the precise conditions leading to the daemon hang were not fully disclosed in the initial vulnerability report, making it challenging for administrators to implement targeted defensive measures.
The operational impact of this vulnerability extends beyond simple service disruption, as the portmapper daemon is essential for RPC-based communication across the system. When the daemon hangs, it prevents new RPC connections from being established and can potentially affect other services that rely on proper RPC mapping for their operation. This can lead to cascading failures where dependent applications and system services become unavailable, significantly impacting system availability and reliability. Network services that depend on RPC protocols such as NFS (Network File System), NIS (Network Information Service), and other distributed applications may experience complete service outages. The vulnerability essentially creates a single point of failure for RPC-based network operations, making it particularly dangerous in enterprise environments where such services are heavily utilized.
Mitigation strategies for CVE-2009-1954 should focus on immediate patching and system hardening measures. Organizations should prioritize applying the vendor-supplied security patches for IBM AIX 5.3 to address the root cause of the vulnerability. System administrators should also implement network segmentation and access controls to limit exposure of the portmapper service to only trusted networks. Monitoring for unusual network traffic patterns and daemon behavior can help detect exploitation attempts. The vulnerability aligns with CWE-119, which deals with memory safety issues, and may relate to ATT&CK technique T1499.004 for endpoint denial of service. Additionally, implementing network intrusion detection systems and regularly reviewing system logs for abnormal daemon behavior can provide early warning of potential exploitation attempts. Given the age of IBM AIX 5.3, organizations should also consider migrating to supported operating system versions to avoid similar vulnerabilities in legacy systems.