CVE-2016-4699 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-2016-4700.
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Analysis
by VulDB Data Team • 09/20/2022
The vulnerability identified as CVE-2016-4699 affects AppleUUC, a component within Apple's OS X operating system that handles universal user interface components. This flaw exists in versions prior to 10.12 and represents a critical security weakness that could enable attackers to execute arbitrary code with elevated privileges or trigger system crashes through carefully crafted applications. The vulnerability operates by exploiting memory corruption issues within the AppleUUC framework, which is responsible for managing user interface elements and system integration components. The flaw demonstrates characteristics of a privilege escalation vulnerability that could potentially allow malicious actors to gain root access to affected systems.
The technical implementation of this vulnerability stems from improper input validation and memory handling within the AppleUUC module. When a malicious application is executed on an affected system, the vulnerable component fails to properly validate memory allocations and data structures, leading to memory corruption that can be exploited to execute arbitrary code. This type of vulnerability falls under the CWE-125 weakness category, which describes out-of-bounds read conditions that can result in memory corruption and privilege escalation. The attack vector specifically involves a crafted application that triggers the memory corruption through improper handling of user interface components, making it particularly dangerous as it can be delivered through seemingly legitimate software installations.
The operational impact of CVE-2016-4699 extends beyond simple denial of service scenarios to encompass full system compromise capabilities. Attackers leveraging this vulnerability could potentially execute code with system-level privileges, allowing them to install malware, modify system files, access sensitive data, or establish persistent backdoors. The memory corruption aspect of the vulnerability means that system stability is also at risk, as the corrupted memory could lead to unpredictable system behavior or complete system crashes. This vulnerability demonstrates the dangerous potential of user interface components to serve as attack vectors, particularly when they operate with elevated privileges and interact with system-level resources. Organizations running affected versions of OS X would face significant risk of compromise, as the vulnerability could be exploited through various attack scenarios including social engineering campaigns or supply chain attacks.
Mitigation strategies for CVE-2016-4699 primarily focus on immediate system updates and operational security measures. The most effective solution involves upgrading to Apple OS X version 10.12 or later, which contains patches addressing the memory corruption issues within AppleUUC. System administrators should implement comprehensive patch management procedures to ensure all affected systems receive the necessary security updates promptly. Additional protective measures include implementing application whitelisting policies to restrict execution of untrusted applications, monitoring system behavior for signs of memory corruption or unusual privilege escalation attempts, and maintaining regular security audits of user interface components. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and may be leveraged as part of broader attack chains involving initial access through malicious applications followed by persistence and lateral movement within compromised environments. Network segmentation and endpoint protection solutions should also be deployed to detect and prevent exploitation attempts, as the vulnerability could be triggered through various delivery methods including email attachments, web downloads, or malicious software installations.