CVE-2018-4162 in iCloud
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.3 is affected. Safari before 11.1 is affected. iCloud before 7.4 on Windows is affected. iTunes before 12.7.4 on Windows is affected. tvOS before 11.3 is affected. watchOS before 4.3 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 • 02/08/2021
The vulnerability identified as CVE-2018-4162 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affects multiple operating systems and applications. This security weakness resides in the core web browsing component that powers Safari, iCloud, iTunes, and various other Apple applications across iOS, tvOS, and watchOS platforms. The vulnerability stems from insufficient input validation and memory management practices within the WebKit framework, creating exploitable conditions that can be leveraged by remote attackers to gain unauthorized system access or disrupt application functionality.
The technical nature of this flaw involves memory corruption that occurs when WebKit processes maliciously crafted web content. Attackers can construct specially designed web pages that trigger buffer overflows, use-after-free conditions, or other memory management errors within the WebKit engine. These conditions manifest when the browser attempts to render complex web elements such as JavaScript objects, HTML documents, or multimedia content that exceeds allocated memory boundaries. The vulnerability specifically affects versions of iOS prior to 11.3, Safari versions before 11.1, iCloud on Windows before version 7.4, iTunes on Windows before version 12.7.4, tvOS before 11.3, and watchOS before 4.3, indicating a widespread impact across Apple's ecosystem.
The operational impact of this vulnerability extends beyond simple application crashes, as it provides attackers with potential pathways for arbitrary code execution. When exploited successfully, the memory corruption can allow remote attackers to execute malicious code with the privileges of the affected application, potentially leading to full system compromise. The vulnerability's remote exploitability means that users can be attacked simply by visiting a malicious website, making it particularly dangerous in phishing campaigns or compromised web hosting environments. Additionally, the denial of service aspect can be used to repeatedly crash applications, rendering them unusable and disrupting normal user operations.
Apple addressed this vulnerability through security updates released as part of iOS 11.3, tvOS 11.3, watchOS 4.3, and corresponding updates for Safari, iCloud, and iTunes on Windows. The remediation involved implementing additional input validation measures, strengthening memory management routines, and patching the specific code paths that were susceptible to buffer overflows and memory corruption attacks. Organizations should prioritize applying these updates immediately to protect their systems from exploitation attempts. The vulnerability aligns with CWE-121, heap-based buffer overflow, and represents a typical example of how browser engine vulnerabilities can provide attackers with elevated privileges through memory corruption techniques. Security professionals should monitor for exploitation attempts and ensure all affected Apple products receive timely security patches to maintain system integrity and prevent unauthorized access through this and similar vulnerabilities.