CVE-2018-4218 in iOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.4 is affected. Safari before 11.1.1 is affected. iCloud before 7.5 on Windows is affected. iTunes before 12.7.5 on Windows is affected. tvOS before 11.4 is affected. watchOS before 4.3.1 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 that triggers an @generatorState use-after-free.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 06/18/2024
The vulnerability identified as CVE-2018-4218 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affects multiple operating systems and applications. This security issue resides in the WebKit component which serves as the core browser engine for Safari, iOS, tvOS, and watchOS platforms, making it a widespread concern across Apple's ecosystem. The vulnerability specifically manifests as a use-after-free condition that occurs when processing crafted web content containing @generatorState directives, creating a dangerous scenario where attackers can manipulate memory references beyond their intended lifecycle.
The technical exploitation of this vulnerability leverages a use-after-free condition classified under CWE-416, where memory allocated to a generatorState object is freed but subsequently accessed by malicious code. This type of memory corruption vulnerability allows attackers to manipulate the application's memory layout and potentially execute arbitrary code with the privileges of the affected application. The flaw exists in how WebKit handles JavaScript generator objects and their internal state management, particularly when processing @generatorState directives that trigger improper memory deallocation followed by unauthorized access attempts.
The operational impact of CVE-2018-4218 extends beyond simple application crashes, as it provides remote attackers with the capability to execute arbitrary code on vulnerable systems. This represents a severe privilege escalation vector that could enable attackers to gain full control over affected devices, potentially leading to data theft, persistent backdoor installation, or further network compromise. The vulnerability affects not only mobile platforms but also desktop operating systems through Safari and iTunes applications, creating multiple attack surfaces for threat actors to exploit.
The attack surface for this vulnerability encompasses any web browsing activity on affected Apple platforms, making it particularly dangerous in phishing campaigns or compromised websites. Attackers can craft malicious web pages that, when loaded in Safari or other affected applications, trigger the memory corruption condition and execute malicious payloads. This vulnerability directly maps to ATT&CK technique T1059.007 for JavaScript execution and T1068 for local privilege escalation, as successful exploitation can lead to system compromise and persistent access.
Mitigation strategies for CVE-2018-4218 primarily focus on immediate patching and system updates to ensure affected Apple products receive the necessary security fixes. Organizations should prioritize updating all affected systems to their latest versions, including iOS 11.4, Safari 11.1.1, iCloud 7.5, iTunes 12.7.5, tvOS 11.4, and watchOS 4.3.1. Additionally, implementing network-level protections such as web content filtering and monitoring for suspicious JavaScript behavior can help detect and prevent exploitation attempts. Security teams should also consider implementing browser hardening measures and monitoring for unusual memory access patterns that may indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and highlights the risks associated with delayed remediation of memory corruption vulnerabilities in widely-used software components.