CVE-2011-1132 in Mac OS X
Summary
by MITRE
The IPv6 implementation in the kernel in Apple Mac OS X before 10.6.8 allows local users to cause a denial of service (NULL pointer dereference and reboot) via vectors involving socket options.
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Analysis
by VulDB Data Team • 11/13/2021
The vulnerability identified as CVE-2011-1132 represents a critical flaw in the IPv6 networking stack of Apple Mac OS X operating systems. This issue affects versions prior to 10.6.8 and demonstrates a classic kernel-level vulnerability that can be exploited by local attackers to disrupt system operations. The flaw specifically manifests within the kernel's handling of socket options during IPv6 protocol processing, creating a pathway for malicious code execution that results in system instability and potential reboot cycles.
The technical root cause of this vulnerability lies in improper input validation and memory management within the kernel's IPv6 implementation. When local users manipulate socket options in specific ways, the kernel's networking subsystem fails to properly validate pointer references, leading to a NULL pointer dereference condition. This type of error falls under the CWE-476 category of NULL Pointer Dereference, which is a well-documented weakness that can lead to system crashes and potential privilege escalation scenarios. The vulnerability exploits the kernel's failure to adequately check socket option parameters before attempting to process them, creating a scenario where malformed input can trigger unexpected behavior in kernel memory management.
From an operational perspective, this vulnerability presents significant risks to Mac OS X systems since it allows local users to trigger a denial of service condition without requiring elevated privileges. The attack vector is particularly concerning because it only requires local access to the system, making it accessible through any user account with basic system access. When exploited successfully, the vulnerability causes the kernel to crash and subsequently reboot the system, effectively creating a denial of service condition that can disrupt legitimate system operations and potentially impact availability for other users or services running on the same machine. This type of local privilege escalation vulnerability aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel exploits.
The impact of this vulnerability extends beyond simple system disruption as it can be leveraged as part of broader attack strategies. Attackers may use this flaw as a stepping stone to gain more persistent access to systems, particularly in environments where multiple users have local access. The vulnerability's location within the kernel's networking stack makes it particularly dangerous because network services and applications that rely on IPv6 functionality could be directly impacted. Organizations running affected versions of Mac OS X should consider this vulnerability as a potential indicator of broader system compromise, especially in cases where unauthorized local access has occurred.
Mitigation strategies for CVE-2011-1132 primarily focus on applying the official security patches provided by Apple through their software update mechanisms. The most effective remediation involves upgrading to Mac OS X 10.6.8 or later versions where Apple has addressed the NULL pointer dereference issue in their IPv6 implementation. System administrators should also implement additional security measures such as restricting local user access where possible, monitoring for unusual system reboot patterns, and ensuring that all system components are kept up to date with the latest security patches. Network segmentation and access controls can help limit the potential impact of local exploitation attempts, while continuous monitoring of system logs can help detect exploitation attempts before they result in successful denial of service conditions.