CVE-2009-2835 in Mac OS X
Summary
by MITRE
The kernel in Apple Mac OS X before 10.6.2 does not properly handle task state segments, which allows local users to gain privileges, cause a denial of service (system crash), or obtain sensitive information via unspecified vectors.
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Analysis
by VulDB Data Team • 06/02/2025
The vulnerability identified as CVE-2009-2835 represents a critical kernel-level flaw in Apple Mac OS X operating systems prior to version 10.6.2. This issue resides within the kernel's handling of task state segments, which are fundamental data structures used by the operating system to manage process execution contexts and maintain system stability. The improper handling of these segments creates exploitable conditions that can be leveraged by local attackers to compromise system integrity and security posture.
The technical flaw manifests in the kernel's inadequate validation and management of task state segments, which are essential components for maintaining process state information during execution. These segments contain critical information about process execution context, including register states, memory management structures, and privilege levels. When the kernel fails to properly validate or handle these segments, it creates opportunities for malicious code to manipulate system memory structures and escalate privileges from standard user level to root access. This vulnerability falls under the category of privilege escalation flaws and can be classified as a CWE-119: Improper Access to Memory Location, which specifically addresses issues where software provides improper access to memory locations.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system crashes and information disclosure. Local attackers can exploit this weakness to cause denial of service conditions that result in system crashes and restarts, disrupting normal operations and potentially causing data loss. Additionally, the vulnerability enables information disclosure attacks where sensitive system information can be accessed and potentially exfiltrated. This combination of privilege escalation, denial of service, and information disclosure creates a comprehensive attack surface that significantly compromises system security and availability.
The exploitability of this vulnerability is particularly concerning as it requires only local access to the system, making it accessible to any user with login credentials. This local privilege escalation capability allows attackers to bypass traditional security measures and gain administrative control over affected systems. The vulnerability's impact is amplified by the fact that it affects the core kernel functionality, meaning that successful exploitation can lead to complete system compromise without requiring additional attack vectors. This type of vulnerability aligns with ATT&CK technique T1068: Exploitation for Privilege Escalation, which specifically targets weaknesses in operating system kernel components to gain elevated privileges.
Mitigation strategies for CVE-2009-2835 primarily focus on applying the official security patches provided by Apple. System administrators should immediately upgrade affected Mac OS X systems to version 10.6.2 or later, which contains the necessary kernel modifications to properly handle task state segments. Additionally, organizations should implement comprehensive system monitoring to detect potential exploitation attempts and maintain regular security assessments to identify any remaining vulnerabilities. The patch addresses the underlying kernel implementation issue by strengthening the validation mechanisms for task state segment handling, thereby preventing the exploitation vectors that lead to privilege escalation and system instability.