CVE-2005-2132 in UnixWare
Summary
by MITRE
RPC portmapper (rpcbind) in SCO UnixWare 7.1.1 m5, 7.1.3 mp5, and 7.1.4 mp2 allows remote attackers or local users to cause a denial of service (lack of response) via multiple invalid portmap requests.
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Analysis
by VulDB Data Team • 07/10/2018
The vulnerability identified as CVE-2005-2132 targets the rpcbind service in SCO UnixWare operating system versions 7.1.1 m5, 7.1.3 mp5, and 7.1.4 mp2. This issue represents a classic denial of service weakness that affects the Remote Procedure Call (RPC) portmapper component responsible for managing RPC service registration and mapping. The rpcbind service operates as a critical infrastructure element that enables RPC clients to discover and connect to RPC servers by maintaining a registry of available services and their corresponding port numbers. When this service becomes unresponsive or crashes due to malformed requests, it fundamentally disrupts the RPC communication framework that many system services depend upon for proper operation.
The technical flaw manifests through the insufficient validation of incoming portmap requests, allowing malicious actors to submit multiple invalid or malformed requests that cause the rpcbind daemon to enter a state where it fails to respond to legitimate RPC service requests. This vulnerability specifically exploits the lack of proper input sanitization and error handling within the portmapper's request processing logic. Attackers can leverage this weakness by crafting specially formatted portmap requests that trigger buffer overflows, memory corruption, or infinite loop conditions within the rpcbind service implementation. The vulnerability falls under the CWE-129 weakness category, which encompasses issues related to improper validation of input boundaries, and represents a significant concern for systems relying on RPC-based communication protocols.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the availability of critical system services that depend on RPC communication. When the rpcbind service becomes unresponsive, it affects not only the immediate RPC functionality but can also impact related services such as NIS (Network Information Service), NFS (Network File System), and other network services that rely on proper port mapping for their operation. This denial of service condition can persist until the rpcbind service is manually restarted or the system is rebooted, creating extended periods of service unavailability that can significantly impact business operations and system reliability. The vulnerability affects both remote attackers who can exploit it over the network and local users who have access to the system, making it particularly dangerous in multi-user environments.
Mitigation strategies for CVE-2005-2132 should focus on immediate system hardening and service management approaches. System administrators should ensure that affected SCO UnixWare systems are updated with the latest security patches provided by SCO or through alternative vendor support channels. Network segmentation and firewall rules should be implemented to restrict access to RPC ports and limit exposure to unauthorized users. Additionally, monitoring solutions should be deployed to detect unusual patterns of portmap requests that could indicate exploitation attempts. The vulnerability demonstrates the importance of implementing proper input validation and error handling in critical system services, aligning with ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also consider implementing intrusion detection systems that can identify and alert on malformed RPC requests that match the characteristics of this vulnerability, providing early warning capabilities for potential exploitation attempts.