CVE-2018-4146 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 attackers to cause a denial of service (memory corruption) via a crafted web site.
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Analysis
by VulDB Data Team • 02/08/2021
The vulnerability identified as CVE-2018-4146 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affects multiple operating systems and applications. This issue resides in the core web browsing component that powers Safari, iCloud, iTunes, and other Apple products, making it particularly dangerous due to its widespread impact across the Apple ecosystem. The vulnerability specifically affects iOS versions prior to 11.3, Safari versions prior to 11.1, iCloud versions prior to 7.4 on Windows, iTunes versions prior to 12.7.4 on Windows, tvOS versions prior to 11.3, and watchOS versions prior to 4.3, indicating a systemic problem within Apple's web rendering infrastructure that required comprehensive patching across multiple platforms.
The technical nature of this vulnerability stems from improper memory handling within WebKit's processing of crafted web content, which can lead to memory corruption when users visit malicious websites. This type of flaw falls under the Common Weakness Enumeration category CWE-125, which describes "Out-of-bounds Read" conditions that can occur when software reads data past the end of a buffer, potentially leading to memory corruption. Attackers can exploit this vulnerability by hosting specially crafted web pages that trigger memory corruption within the WebKit engine, causing applications to crash or behave unpredictably, resulting in denial of service conditions that can severely impact user experience and system stability.
The operational impact of CVE-2018-4146 extends beyond simple application crashes, as it represents a potential gateway for more sophisticated attacks within the Apple ecosystem. When memory corruption occurs in WebKit, it can provide attackers with opportunities to execute arbitrary code or escalate privileges, particularly given that many Apple applications rely heavily on WebKit for web content rendering. The vulnerability's presence across multiple platforms including mobile, desktop, and embedded systems means that users could be compromised regardless of their device type, making this an attractive target for threat actors seeking broad exploitation capabilities. The fact that Windows versions of iCloud and iTunes are affected further expands the potential attack surface, as these applications often handle sensitive user data and may be targeted by attackers seeking to compromise user accounts or access stored information.
Mitigation strategies for CVE-2018-4146 primarily involve immediate patching of affected systems through Apple's official software updates, which address the underlying memory corruption issues in WebKit. Organizations should implement comprehensive vulnerability management processes to ensure all Apple products within their environment receive timely updates, particularly given the vulnerability's potential for remote code execution. Network administrators should consider implementing web filtering solutions and monitoring for suspicious web traffic that may indicate attempts to exploit this vulnerability. The ATT&CK framework categorizes this type of vulnerability under T1059.006 for "Command and Scripting Interpreter: JavaScript", as attackers may leverage JavaScript within malicious websites to trigger the memory corruption. Additionally, users should be educated about avoiding untrusted websites and maintaining current software versions to minimize exposure risk, as this vulnerability demonstrates the critical importance of keeping web browsers and related applications updated to prevent exploitation of memory corruption flaws that can lead to complete system compromise.