CVE-2009-1237 in Mac OS X
Summary
by MITRE
Multiple memory leaks in XNU 1228.3.13 and earlier on Apple Mac OS X 10.5.6 and earlier allow local users to cause a denial of service (kernel memory consumption) via a crafted (1) SYS_add_profil or (2) SYS___mac_getfsstat system call.
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Analysis
by VulDB Data Team • 11/25/2024
The vulnerability identified as CVE-2009-1237 represents a critical memory management flaw within the XNU kernel, which serves as the foundation for Apple's Mac OS X operating system. This issue affects XNU versions 1228.3.13 and earlier, impacting Mac OS X 10.5.6 and previous releases. The vulnerability stems from insufficient memory deallocation mechanisms within two specific system calls, namely SYS_add_profil and SYS___mac_getfsstat, which are integral components of the kernel's privilege escalation and file system monitoring capabilities.
The technical implementation of this vulnerability involves improper handling of memory allocation and deallocation routines within the kernel space. When a local user executes a crafted system call with specific parameters, the kernel fails to properly release allocated memory segments, leading to gradual memory consumption over time. This memory leak occurs in the kernel's memory management subsystem, where allocated memory blocks are not correctly freed after system call processing. The vulnerability manifests through the two identified system calls that handle profiling data collection and MAC (Mandatory Access Control) file system statistics, both of which require elevated privileges to execute. The flaw specifically affects the kernel's ability to manage memory resources efficiently, creating a condition where repeated exploitation can exhaust available kernel memory.
The operational impact of CVE-2009-1237 is significant as it enables a local attacker to perform a denial of service attack against the target system. By repeatedly invoking the vulnerable system calls, an attacker can gradually consume all available kernel memory, eventually causing system instability and potential kernel panics. The attack requires local access to the system, making it a privilege escalation vector that could be exploited by users with standard account privileges. This vulnerability particularly affects systems running older versions of Mac OS X where the memory management fixes have not been implemented. The memory consumption occurs at the kernel level, making it difficult for the operating system to recover gracefully, and potentially leading to complete system lockups or forced reboots.
Mitigation strategies for this vulnerability include immediate system updates to newer versions of Mac OS X where the memory leak has been addressed through proper kernel memory management implementations. System administrators should ensure that all Mac OS X systems are updated to versions containing the patched XNU kernel, particularly those released after the vulnerability disclosure. Additionally, monitoring for unusual memory consumption patterns and implementing system hardening measures can help detect potential exploitation attempts. The vulnerability aligns with CWE-401, which catalogs memory leak issues in software systems, and represents a classic example of improper resource management that can lead to denial of service conditions. From an ATT&CK framework perspective, this vulnerability falls under privilege escalation techniques and resource exhaustion methods, demonstrating how kernel-level memory management flaws can be exploited by adversaries to compromise system availability. Organizations should also consider implementing kernel extension monitoring and system call auditing to detect potential exploitation attempts and maintain comprehensive system integrity controls.