CVE-2009-0874 in OpenSolaris
Summary
by MITRE
Multiple unspecified vulnerabilities in the Doors subsystem in the kernel in Sun Solaris 8 through 10, and OpenSolaris before snv_94, allow local users to cause a denial of service (process hang), or possibly bypass file permissions or gain kernel-context privileges, via vectors including ones related to (1) an argument handling deadlock in a door server and (2) watchpoint problems in the door_call function.
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Analysis
by VulDB Data Team • 08/31/2019
The vulnerability identified as CVE-2009-0874 resides within the Doors subsystem of Sun Solaris operating systems spanning versions 8 through 10, as well as OpenSolaris prior to snv_94 release. This critical flaw affects the kernel-level implementation of the doors mechanism, which serves as a communication interface between user-space processes and kernel-space components. The doors subsystem facilitates inter-process communication and provides a means for applications to invoke kernel functions through a well-defined interface. The vulnerability manifests through two distinct but related attack vectors that exploit fundamental weaknesses in the kernel's handling of door server arguments and the door_call function's watchpoint implementation.
The technical exploitation of this vulnerability involves two primary attack paths that leverage different aspects of the doors subsystem's architecture. The first vector involves an argument handling deadlock within a door server, where improper synchronization mechanisms cause processes to enter indefinite waiting states when processing door server arguments. This deadlock condition results in process hangs that can effectively constitute a denial of service against legitimate system operations. The second vector targets watchpoint problems within the door_call function, which represents a critical kernel interface for invoking door server routines. When watchpoints are improperly managed during door_call execution, attackers can potentially bypass file permission checks or escalate privileges to kernel context, as the watchpoint mechanisms are designed to monitor and control access to kernel resources.
The operational impact of CVE-2009-0874 extends beyond simple denial of service scenarios to encompass serious security implications including privilege escalation and potential system compromise. Local attackers with minimal privileges can exploit these vulnerabilities to either freeze system processes through deadlock conditions or gain unauthorized access to kernel-level resources. The privilege escalation aspect particularly concerns security professionals as it could allow attackers to execute code with kernel privileges, potentially leading to complete system compromise. The vulnerability's presence in multiple Solaris versions demonstrates the widespread nature of the flaw and its persistence across different kernel implementations, making it particularly dangerous for organizations maintaining legacy systems.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-121, which addresses buffer overflow conditions, and CWE-362, which covers concurrent execution using shared resources. The deadlock condition in door server argument handling represents a classic resource contention issue that violates proper synchronization protocols. Additionally, the privilege escalation potential maps to ATT&CK technique T1068, which covers local privilege escalation through kernel exploits. The vulnerability also demonstrates characteristics of T1499, which involves disruption of services through resource exhaustion or process hanging. Organizations should consider implementing process monitoring and resource limiting mechanisms to detect and prevent exploitation attempts, while also ensuring timely patch deployment to address the underlying kernel flaws.
Mitigation strategies for CVE-2009-0874 require a multi-layered approach that combines immediate operational controls with long-term system hardening. System administrators should prioritize patching affected Solaris systems to the latest available security updates from Sun Microsystems, particularly focusing on kernel-level fixes that address the specific door server argument handling and watchpoint implementation issues. Network segmentation and access controls can help limit the potential impact of successful exploitation by restricting local access to affected systems. Implementing process monitoring solutions that can detect abnormal process hanging behavior or unexpected privilege escalation attempts provides additional layers of defense. Regular security assessments should verify that door server configurations follow secure implementation practices, including proper argument validation and synchronization mechanisms. Organizations maintaining legacy Solaris systems should also consider implementing intrusion detection systems specifically tuned to detect exploitation attempts targeting the doors subsystem, as these attacks may not be immediately obvious through standard security monitoring approaches.