CVE-2016-4586 in tvOS
Summary
by MITRE
WebKit in Apple Safari before 9.1.2 and tvOS before 9.2.2 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site.
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Analysis
by VulDB Data Team • 09/06/2022
The vulnerability identified as CVE-2016-4586 represents a critical memory corruption flaw within the WebKit rendering engine that powers Apple Safari browsers and tvOS web environments. This vulnerability affects versions prior to Safari 9.1.2 and tvOS 9.2.2, creating a significant attack surface for remote threat actors who can exploit this weakness through maliciously crafted websites. The flaw resides in how WebKit processes certain web content, specifically in the manner in which it handles memory allocation and deallocation during web page rendering operations.
The technical nature of this vulnerability stems from improper memory management within WebKit's JavaScript engine and HTML parsing components. Attackers can construct web pages containing specially crafted malicious code that triggers buffer overflows or use-after-free conditions when the browser attempts to render specific elements. These memory corruption issues occur when the browser allocates memory for web content and subsequently accesses that memory in an unauthorized manner, potentially leading to arbitrary code execution or system crashes. The vulnerability is classified under CWE-125 as an out-of-bounds read condition and may also involve CWE-787 for out-of-bounds write operations, depending on the specific exploitation vector.
The operational impact of CVE-2016-4586 extends beyond simple denial of service scenarios to encompass full system compromise capabilities. Remote attackers can leverage this vulnerability to execute arbitrary code on affected systems without requiring user interaction, making it particularly dangerous for enterprise environments and individual users who browse the internet. The memory corruption can be exploited through various web-based attack vectors including malicious advertisements, compromised websites, or phishing pages that automatically execute the malicious payload when loaded in Safari. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1203 for Exploitation for Client Execution, enabling adversaries to establish persistent access to compromised systems.
Mitigation strategies for CVE-2016-4586 primarily focus on immediate system updates and patch management procedures. Apple released security updates for Safari 9.1.2 and tvOS 9.2.2 that address the memory corruption issues through improved bounds checking and memory management routines within WebKit. Organizations should implement comprehensive patch management policies ensuring all affected systems receive updates promptly, while also considering network-based protections such as web application firewalls and content filtering solutions. Additional defensive measures include browser hardening configurations, sandboxing implementations, and user education regarding safe browsing practices to minimize exposure to malicious websites. The vulnerability underscores the importance of maintaining current security patches and demonstrates how rendering engine flaws can provide attackers with direct paths to system compromise through seemingly benign web browsing activities.