CVE-2016-4764 in tvOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10 is affected. Safari before 10 is affected. iTunes before 12.5.1 is affected. tvOS before 10 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 • 08/16/2020
This vulnerability resides within Apple's WebKit rendering engine, which serves as the core component powering Safari web browser and numerous other applications across Apple's ecosystem. The flaw represents a critical memory corruption issue that affects multiple Apple platforms including iOS versions prior to 10, Safari versions before 10, iTunes versions before 12.5.1, and tvOS versions before 10. The vulnerability stems from improper handling of memory allocations and deallocations when processing crafted web content, creating opportunities for malicious actors to exploit memory management flaws through web-based attacks. This type of vulnerability typically falls under CWE-122, which describes buffer overflow conditions that can lead to memory corruption, and aligns with ATT&CK technique T1059.1001 for abuse of web shell commands and T1203 for exploitation of remote services. The attack vector requires a remote malicious website to be visited by an unsuspecting user, making it particularly dangerous for widespread exploitation. The vulnerability can be leveraged to execute arbitrary code on the target system or cause denial of service conditions through application crashes, effectively compromising the integrity and availability of affected Apple devices. The memory corruption aspect of this flaw means that attackers can manipulate memory addresses and control program execution flow, potentially leading to complete system compromise. This vulnerability demonstrates the inherent risks in complex web rendering engines where memory management errors can translate into severe security breaches. The impact extends beyond individual user devices to potentially affect enterprise environments where Apple products are prevalent. Security researchers have identified that the flaw occurs during the processing of specific web content structures that trigger improper memory handling within WebKit's JavaScript engine integration. The exploitation process typically involves crafting malicious web pages that, when rendered by the vulnerable WebKit component, trigger the memory corruption bug. This vulnerability represents a classic example of how browser-based attacks can leverage rendering engine flaws to achieve privilege escalation and persistent access to target systems. The affected platforms represent a significant portion of Apple's user base at the time of disclosure, making this vulnerability particularly concerning from a threat perspective. The memory corruption nature of the flaw means that it can be used for both remote code execution and denial of service attacks, providing attackers with multiple exploitation options. This vulnerability underscores the importance of timely security updates and patch management processes, as the exploitation window remains open for users who have not applied the necessary security patches. The WebKit component's extensive integration across Apple's software ecosystem means that exploitation of this vulnerability can potentially affect multiple applications simultaneously, amplifying the attack surface. Security professionals should note that this vulnerability requires no user interaction beyond visiting a malicious website, making it particularly dangerous in phishing campaigns or compromised websites. The remediation process involves updating to the patched versions of the affected software components, which typically include memory management improvements and additional input validation controls. This vulnerability highlights the ongoing challenge of securing complex software components like rendering engines that must handle vast amounts of untrusted data from web content. Organizations should implement network monitoring to detect potential exploitation attempts and ensure rapid deployment of security patches across their Apple device fleets. The vulnerability's classification as a memory corruption issue places it within the category of advanced persistent threats that can be leveraged for sophisticated attacks requiring minimal user interaction. This particular flaw exemplifies how seemingly minor memory handling issues in core software components can result in severe security implications across an entire platform ecosystem. The exploitation techniques for this vulnerability align with common attack patterns found in the cybersecurity community, where memory corruption vulnerabilities serve as primary targets for attackers seeking to establish persistent access to systems.