CVE-2016-4700 in macOS
Summary
by MITRE
AppleUUC in Apple OS X before 10.12 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app, a different vulnerability than CVE-2016-4699.
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Analysis
by VulDB Data Team • 09/20/2022
The vulnerability identified as CVE-2016-4700 affects AppleUUC, a component within Apple's macOS operating system that handles Universal User Control functionality. This flaw exists in versions prior to macOS 10.12 and represents a critical security weakness that could be exploited by malicious actors to gain elevated privileges or disrupt system operations. The vulnerability specifically relates to how AppleUUC processes crafted applications, creating opportunities for arbitrary code execution within privileged contexts. This issue is distinct from CVE-2016-4699, which indicates that attackers can leverage a specially crafted application to trigger memory corruption that leads to privilege escalation or denial of service conditions. The technical implementation involves improper input validation within the AppleUUC component, which fails to properly sanitize or verify application data before processing, creating a pathway for malicious code injection.
The operational impact of CVE-2016-4700 extends beyond simple privilege escalation to encompass potential system instability and complete compromise of affected macOS installations. When exploited, this vulnerability allows attackers to execute arbitrary code with elevated privileges, effectively bypassing standard security controls and access restrictions. The memory corruption aspect of the flaw can result in system crashes or reboots, creating denial of service conditions that could be leveraged for persistent disruption of services. Organizations running macOS versions prior to 10.12 face significant risk exposure, as this vulnerability could enable attackers to establish persistent backdoors, exfiltrate sensitive data, or deploy additional malware payloads. The privileged execution context provided by this flaw makes it particularly dangerous for enterprise environments where macOS systems may serve as targets for advanced persistent threats or insider attacks.
Security professionals should consider this vulnerability in the context of established frameworks such as CWE classification, where this issue aligns with CWE-121, heap-based buffer overflow, and CWE-787, out-of-bounds write, which are common patterns in kernel and system-level vulnerabilities. The attack surface for CVE-2016-4700 maps to several ATT&CK techniques including privilege escalation through exploitation of software vulnerabilities and execution through legitimate system processes. Mitigation strategies should focus on immediate patching of affected systems to macOS 10.12 or later versions where the vulnerability has been addressed. Additionally, network administrators should implement monitoring for suspicious application execution patterns and consider deploying endpoint protection solutions that can detect anomalous behavior associated with privilege escalation attempts. System hardening measures including restricting user privileges and implementing application whitelisting can provide additional defense-in-depth layers. Organizations should also conduct thorough vulnerability assessments to identify any systems running unsupported macOS versions and ensure comprehensive patch management processes are in place to prevent similar vulnerabilities from remaining unaddressed in future releases.
The broader implications of CVE-2016-4700 highlight the importance of maintaining up-to-date operating system installations and the risks associated with legacy software support. This vulnerability demonstrates how system-level components can serve as attack vectors for sophisticated adversaries seeking to establish persistent access to target environments. The distinction from CVE-2016-4699 underscores the complexity of macOS security architecture and the need for comprehensive vulnerability management programs that address multiple related issues within the same software ecosystem. Organizations should integrate this vulnerability into their risk assessment frameworks and consider the potential for similar flaws in other system components that handle privileged operations or user input processing.