CVE-2016-4666 in tvOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.1 is affected. Safari before 10.0.1 is affected. tvOS before 10.0.1 is affected. The issue involves the "WebKit" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 09/28/2022
The vulnerability identified as CVE-2016-4666 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affected multiple Apple operating systems and applications. This vulnerability resides in the core web browsing component that powers Safari and other Apple applications, making it particularly dangerous as it can be exploited through standard web browsing activities without requiring any special privileges or user interaction beyond visiting a malicious website. The affected versions include iOS prior to 10.1, Safari prior to 10.0.1, and tvOS prior to 10.0.1, indicating a broad attack surface that could potentially compromise a wide range of Apple devices including iPhones, iPads, Apple TVs, and Mac computers running these vulnerable versions. The WebKit component serves as the foundation for web content rendering across Apple's ecosystem, making this vulnerability particularly severe as it could be leveraged to gain unauthorized access to sensitive information or execute malicious code on target devices.
The technical nature of this vulnerability involves memory corruption that occurs when WebKit processes specially crafted web content, leading to unpredictable behavior that can result in either arbitrary code execution or denial of service conditions. Memory corruption vulnerabilities typically arise from improper handling of memory allocation, deallocation, or bounds checking during web content processing, creating opportunities for attackers to manipulate memory layout or inject malicious code into the running process. This type of vulnerability is classified under CWE-122 as "Heap-based Buffer Overflow" or similar memory corruption categories, and aligns with ATT&CK technique T1059.006 for "Command and Scripting Interpreter: PowerShell" when considering the potential for code execution, though the specific exploitation mechanism in this case involves WebKit's memory management rather than script-based attacks. The vulnerability's remote exploitation capability means that attackers can craft malicious websites that, when loaded in Safari or other affected applications, automatically trigger the memory corruption without requiring user interaction beyond navigation to the malicious site.
The operational impact of CVE-2016-4666 extends far beyond simple denial of service conditions, as the potential for arbitrary code execution creates serious security implications for users of affected Apple devices. Attackers could leverage this vulnerability to install malicious software, steal sensitive data, monitor user activities, or establish persistent access to compromised systems. The vulnerability's presence in the WebKit engine means that even legitimate websites could potentially be compromised through supply chain attacks or if attackers manage to inject malicious content into otherwise trusted sites. Organizations and individuals using affected versions of Apple software faced significant risk exposure, as the vulnerability could be exploited in the wild without requiring any specialized knowledge or tools beyond basic web-based attack techniques. The widespread use of Safari and Apple's web browsing capabilities across personal and enterprise environments amplified the potential impact, as a single compromised website could affect thousands of users simultaneously.
Mitigation strategies for CVE-2016-4666 focused primarily on immediate software updates and patches provided by Apple to address the underlying memory corruption issue in WebKit. Users were strongly advised to upgrade to the latest available versions of iOS, Safari, and tvOS to eliminate exposure to this vulnerability. Network administrators and security teams implemented additional protective measures including web filtering, browser security hardening, and monitoring for suspicious web traffic patterns that might indicate exploitation attempts. The vulnerability highlighted the importance of keeping web browsers and operating systems current, as the memory corruption issue was resolved through Apple's security updates that addressed the specific WebKit memory handling flaws. Security professionals recommended implementing multi-layered defenses including web application firewalls, content security policies, and regular security assessments to reduce the risk of exploitation, while also emphasizing the critical role of timely patch management in protecting against known vulnerabilities. Organizations with Apple device fleets needed to establish robust update deployment processes to ensure all affected systems received security patches promptly, as the vulnerability's remote exploitation capability made it particularly dangerous in enterprise environments where multiple devices might be simultaneously exposed to attack.