CVE-2018-4118 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. 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-2018-4118 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affects multiple platforms and applications. This issue resides in the core web browsing component that powers Safari, iCloud, iTunes, and tvOS applications across various Apple ecosystems. The vulnerability stems from improper memory handling mechanisms within WebKit's JavaScript engine, specifically when processing malformed or crafted web content that triggers buffer overflows or memory corruption conditions. Security researchers have classified this as a remote code execution vulnerability due to its ability to allow attackers to execute arbitrary code on affected systems simply by visiting a malicious website.
The technical exploitation of this vulnerability occurs through carefully crafted web pages that leverage memory corruption patterns to overwrite critical memory segments or execute malicious code within the context of the affected applications. When users navigate to compromised websites, the WebKit component processes the malicious content and triggers the memory corruption, potentially leading to complete system compromise or application crashes. This flaw demonstrates characteristics consistent with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds writes. The vulnerability operates at the intersection of memory management and web rendering, making it particularly dangerous as it can be exploited through standard web browsing activities without requiring any special privileges or user interaction beyond visiting a malicious site.
The operational impact of CVE-2018-4118 extends across Apple's entire ecosystem of devices and applications, affecting iOS versions prior to 11.3, Safari versions before 11.1, iCloud on Windows versions before 7.4, iTunes on Windows versions before 12.7.4, and tvOS versions before 11.3. This widespread impact makes the vulnerability particularly concerning for enterprise environments where Apple devices are prevalent, as a single compromised website can potentially affect multiple devices and applications simultaneously. The vulnerability's remote nature means that attackers can exploit it without physical access to devices, making it a significant threat vector for man-in-the-middle attacks, drive-by downloads, or phishing campaigns targeting Apple users. Organizations using these affected versions face potential data breaches, system compromise, and denial of service conditions that could disrupt business operations.
Mitigation strategies for CVE-2018-4118 primarily involve immediate software updates and patches provided by Apple to address the underlying memory corruption issues within WebKit. Organizations should prioritize updating all affected Apple platforms to their latest versions, including iOS 11.3, Safari 11.1, iCloud 7.4, iTunes 12.7.4, and tvOS 11.3. Network administrators should implement web filtering solutions and browser security controls to prevent access to known malicious domains, while also monitoring for exploitation attempts through intrusion detection systems. Security teams should conduct comprehensive vulnerability assessments across their Apple device fleets to identify and remediate affected systems. The ATT&CK framework categorizes this vulnerability under T1059.007 for command and scripting interpreter, as exploitation typically involves JavaScript-based attacks that leverage the browser's scripting capabilities. Additionally, organizations should consider implementing application whitelisting policies and restricting web browsing to trusted domains to reduce the attack surface. Regular security monitoring and incident response procedures should be enhanced to detect potential exploitation attempts, as the vulnerability's memory corruption characteristics may not always result in immediate system crashes but could lead to more subtle exploitation patterns over time.