CVE-2018-4089 in Safari
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.2.5 is affected. macOS before 10.13.3 is affected. Safari before 11.0.3 is affected. tvOS before 11.2.5 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.
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Analysis
by VulDB Data Team • 06/16/2024
The vulnerability identified as CVE-2018-4089 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affected multiple operating systems and applications. This vulnerability resides in the core web browsing component that powers Safari, iOS web views, and other Apple products that utilize WebKit for web content rendering. The flaw manifests as a heap-based buffer overflow or memory corruption issue that occurs when processing specially crafted web content, allowing attackers to manipulate memory structures in ways that can lead to arbitrary code execution or system instability.
The technical nature of this vulnerability stems from improper input validation and memory management within WebKit's JavaScript engine and HTML parser components. Attackers can craft malicious websites containing specifically formatted JavaScript code, HTML elements, or embedded resources that trigger the memory corruption when processed by the vulnerable WebKit engine. The flaw typically occurs during dynamic memory allocation or when handling complex web page structures, particularly involving object manipulation, array operations, or memory-intensive JavaScript computations. This type of vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations, both of which are common categories for memory corruption vulnerabilities in web browsers.
The operational impact of CVE-2018-4089 extends across multiple Apple platforms including iOS, macOS, and tvOS, making it a particularly dangerous vulnerability for the Apple ecosystem. When exploited, the vulnerability can result in complete system compromise, allowing attackers to execute arbitrary code with the privileges of the affected application, typically Safari or the iOS web view. The remote exploitation capability means that users can be compromised simply by visiting a malicious website, making this a zero-click attack vector that requires no user interaction beyond normal browsing behavior. Additionally, the vulnerability can cause denial of service conditions that crash applications or even entire operating systems, disrupting normal user operations and potentially enabling further attack vectors through system instability.
The attack surface for this vulnerability encompasses all web browsing activities on affected Apple products, including regular web surfing, email link clicks, and even embedded web content in applications. Security researchers have documented how attackers can leverage this vulnerability through techniques such as memory spraying, return-oriented programming, or just-in-time compilation attacks that take advantage of the memory corruption to gain code execution privileges. The ATT&CK framework categorizes this type of vulnerability under techniques related to code injection and privilege escalation, as the exploitation typically involves bypassing memory protection mechanisms and executing malicious code in legitimate application contexts. Organizations and users affected by this vulnerability should prioritize immediate patching of their systems, as the window for exploitation was significant and the impact could be severe across the entire Apple platform ecosystem.
Mitigation strategies for CVE-2018-4089 primarily focus on applying the official security patches released by Apple, which include iOS 11.2.5, macOS 10.13.3, Safari 11.0.3, and tvOS 11.2.5 updates. Network administrators should implement web filtering solutions and browser hardening measures to reduce exposure, while users should avoid visiting untrusted websites and maintain updated security software. Additional protective measures include enabling sandboxing features, using secure browsing configurations, and implementing monitoring solutions to detect potential exploitation attempts. The vulnerability highlights the importance of regular security updates and the need for organizations to maintain comprehensive patch management processes to protect against similar memory corruption vulnerabilities in web browser components.