CVE-2009-1673 in Solaris
Summary
by MITRE
The kernel in Sun Solaris 9 allows local users to cause a denial of service (panic) by calling fstat with a first argument of AT_FDCWD.
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Analysis
by VulDB Data Team • 04/13/2025
The vulnerability identified as CVE-2009-1673 represents a critical kernel-level flaw in Sun Solaris 9 systems that enables local attackers to trigger system panics through improper handling of file system operations. This issue specifically manifests when the fstat system call is invoked with the AT_FDCWD constant as its first argument, a scenario that should not normally cause system instability but instead results in kernel panic conditions that completely disrupt system operation.
The technical root cause of this vulnerability lies in the kernel's improper validation and handling of the AT_FDCWD argument within the fstat system call implementation. When a local user executes a program that calls fstat with AT_FDCWD as the file descriptor parameter, the kernel fails to properly validate this input, leading to an invalid memory access or buffer overflow condition that ultimately results in system panic. This flaw demonstrates a classic lack of proper input sanitization and boundary checking within kernel space operations, which is categorized under CWE-129 Input Validation and Output Format issues.
From an operational perspective, this vulnerability presents significant risks for Solaris 9 environments as it allows any local user to potentially crash the entire system without requiring elevated privileges. The impact extends beyond simple denial of service since a system panic can result in data loss, service interruption, and potential compromise of system integrity. Attackers could exploit this vulnerability repeatedly to maintain persistent system disruption, making it particularly dangerous in production environments where system availability is critical.
The security implications of CVE-2009-1673 align with ATT&CK technique T1499.004 Network Denial of Service, though specifically targeting the local system rather than network services. This vulnerability also relates to the broader category of privilege escalation and system stability compromise under ATT&CK framework. The exploit requires minimal privileges since it targets a local user account, but the potential for system-wide disruption makes it a serious concern for system administrators.
Mitigation strategies for this vulnerability include applying the official Sun Microsystems security patches that address the kernel implementation flaw in the fstat system call handling. System administrators should prioritize patching affected Solaris 9 systems and consider implementing additional security measures such as restricting local user privileges and monitoring for unusual system call patterns. Regular system updates and vulnerability assessments remain crucial for maintaining system integrity, particularly for legacy systems running unsupported operating system versions. Organizations should also consider implementing monitoring solutions that can detect and alert on abnormal system behavior that might indicate exploitation attempts.