CVE-2016-4729 in iOS
Summary
by MITRE
WebKit in Apple iOS before 10 and Safari before 10 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, a different vulnerability than CVE-2016-4731.
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Analysis
by VulDB Data Team • 09/20/2022
The vulnerability identified as CVE-2016-4729 represents a critical memory corruption flaw within WebKit, the rendering engine that powers Apple's Safari browser and iOS web browsing capabilities. This vulnerability affects iOS versions prior to 10.0 and Safari versions before 10.0, creating a significant attack surface for remote threat actors who can leverage malicious websites to compromise affected systems. The flaw resides in how WebKit processes certain web content, specifically in memory management operations that lead to unpredictable behavior when handling crafted web pages.
The technical implementation of this vulnerability involves sophisticated memory corruption techniques that enable attackers to manipulate heap memory structures within the WebKit process. When users visit a maliciously crafted website, the vulnerable code path triggers memory corruption that can be exploited to achieve arbitrary code execution on the target system. This type of vulnerability typically occurs when WebKit fails to properly validate or sanitize input data during web page rendering, leading to buffer overflows, use-after-free conditions, or other memory management errors that create opportunities for exploitation. The vulnerability operates at the intersection of browser engine security and memory safety mechanisms, making it particularly dangerous due to its ability to bypass standard security protections.
The operational impact of CVE-2016-4729 extends far beyond simple denial of service scenarios, as it enables full remote code execution capabilities that can result in complete system compromise. Attackers can leverage this vulnerability to install malware, steal sensitive data, monitor user activity, or establish persistent backdoors on affected devices. The remote nature of the attack means that users can be compromised simply by visiting a malicious website, without requiring any additional interaction or user deception beyond the initial visit. This makes the vulnerability particularly dangerous in phishing campaigns or when exploited through compromised websites that users might naturally visit, such as news sites, social media platforms, or other commonly accessed web resources.
Organizations and individual users affected by this vulnerability should prioritize immediate remediation through official Apple updates and security patches. The mitigation strategy involves upgrading to iOS 10.0 or later and Safari 10.0 or later, which contain the necessary fixes to address the memory corruption issues within WebKit. Additionally, security professionals should implement network monitoring to detect potential exploitation attempts and consider deploying browser security extensions or sandboxing solutions as additional protective measures. This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and represents a classic example of how browser engine vulnerabilities can create pathways for privilege escalation and complete system compromise. The ATT&CK framework categorizes this type of vulnerability under T1203, which encompasses exploitation for client execution, emphasizing the need for comprehensive defense-in-depth strategies that address both endpoint and network-level protections.