CVE-2016-7604 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12.2 is affected. The issue involves the "CoreCapture" component. It allows local users to cause a denial of service (NULL pointer dereference) via unspecified vectors.
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Analysis
by VulDB Data Team • 10/07/2022
The vulnerability identified as CVE-2016-7604 resides within Apple's macOS operating system and specifically targets the CoreCapture component that is part of the system's multimedia and capture functionality. This flaw represents a critical security weakness that affects macOS versions prior to 10.12.2, leaving millions of Apple devices potentially vulnerable to exploitation. The CoreCapture component is responsible for handling media capture operations and integrates deeply with the system's kernel and user-space applications. This particular vulnerability manifests as a NULL pointer dereference condition that occurs when the system processes certain malformed inputs or capture requests. The flaw was classified under CWE-476 which specifically addresses NULL pointer dereference vulnerabilities, where a program attempts to access memory through a null pointer reference, leading to system instability and potential crashes. The vulnerability's impact extends beyond simple system instability as it provides a pathway for local users to execute denial of service attacks that can disrupt normal system operations.
The technical exploitation of CVE-2016-7604 occurs when a local attacker crafts specific input parameters that trigger the CoreCapture component to attempt accessing a NULL memory pointer. This type of vulnerability typically arises from inadequate input validation or error handling within the system's kernel extensions or system frameworks. When the CoreCapture component encounters malformed data during media capture operations, it fails to properly validate the input before attempting to dereference pointers, leading to a system crash or reboot. The vulnerability's nature as a NULL pointer dereference places it squarely within the ATT&CK framework under the T1499.004 technique category for "Endpoint Denial of Service" which encompasses attacks that target system resources to prevent normal operation. The exploitation vector is particularly concerning because it requires no special privileges beyond local user access, making it accessible to any user with login credentials on the affected system. The vulnerability's impact is amplified by the fact that CoreCapture is deeply integrated into macOS's multimedia subsystem, meaning that even simple media operations could trigger the flaw.
From an operational perspective, the implications of CVE-2016-7604 extend beyond simple system crashes and can severely impact productivity and system availability in enterprise environments. The vulnerability can be exploited to disrupt critical business operations by causing unexpected system reboots or application failures, particularly in scenarios where automated media capture processes are in use. The local nature of the exploit means that it can be leveraged by malicious insiders or attackers who have already gained user-level access to a system. This makes the vulnerability particularly dangerous in environments where users have elevated privileges or where privilege escalation techniques are already in place. Organizations running macOS versions prior to 10.12.2 face significant risk of service disruption, potential data loss, and increased operational overhead as system administrators must monitor and respond to the increased frequency of system crashes. The vulnerability also impacts the overall security posture by creating a persistent attack surface that can be used as a stepping stone for more sophisticated attacks, as system instability can mask other security issues or provide opportunities for privilege escalation attempts.
Mitigation strategies for CVE-2016-7604 focus primarily on updating to the patched version of macOS 10.12.2 or later, which resolves the underlying NULL pointer dereference issue in the CoreCapture component. System administrators should prioritize patch deployment across all affected macOS systems, particularly in enterprise environments where the risk of exploitation is higher. Additional defensive measures include implementing proper input validation controls within applications that interact with multimedia capture functionality and monitoring system logs for unusual patterns that might indicate exploitation attempts. Organizations should also consider implementing network segmentation and access controls to limit local user access where possible, reducing the attack surface for local privilege escalation attempts. The vulnerability serves as a reminder of the importance of maintaining current system patches and the critical role that timely security updates play in protecting against known vulnerabilities. Security teams should also consider implementing automated monitoring solutions that can detect system instability patterns associated with denial of service attacks, providing early warning capabilities for potential exploitation attempts. The remediation process should include thorough testing of patches in controlled environments before widespread deployment to ensure compatibility with existing enterprise applications and workflows.