CVE-2018-4096 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. iCloud before 7.3 on Windows is affected. iTunes before 12.7.3 on Windows is affected. tvOS before 11.2.5 is affected. watchOS before 4.2.2 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 • 02/02/2021
The vulnerability identified as CVE-2018-4096 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affected multiple Apple operating systems and applications. This vulnerability resides in the core web browsing component responsible for rendering web content across Apple's ecosystem, making it a prime target for remote exploitation. The affected versions include iOS 11.2.4 and earlier, macOS 10.13.2 and earlier, Safari 11.0.2 and earlier, iCloud 7.2 and earlier on Windows, iTunes 12.7.2 and earlier on Windows, tvOS 11.2.4 and earlier, and watchOS 4.2.1 and earlier, demonstrating the widespread impact across Apple's product portfolio.
The technical nature of this vulnerability stems from improper memory handling within WebKit's JavaScript engine, specifically when processing crafted web content. Attackers can exploit this flaw by hosting malicious web pages that trigger memory corruption conditions during normal web browsing operations. The vulnerability allows for arbitrary code execution, enabling attackers to gain full control over affected systems, or alternatively cause denial of service conditions that result in application crashes and system instability. This memory corruption occurs during the parsing and execution of JavaScript code, where insufficient bounds checking or improper memory management leads to exploitable conditions that can be leveraged remotely.
The operational impact of CVE-2018-4096 extends beyond individual device compromise to potentially affect entire Apple ecosystems where WebKit is integrated. Given that Safari, iTunes, iCloud, and other applications rely on WebKit for web content rendering, the attack surface is extensive and includes both personal and enterprise environments. The vulnerability's remote exploitation capability means that users need only visit a malicious website to be compromised, making it particularly dangerous in phishing campaigns or compromised advertising networks. The memory corruption can result in complete system compromise, allowing attackers to execute malicious code with the privileges of the affected application, potentially leading to data theft, system takeover, or persistent backdoor installation.
Mitigation strategies for CVE-2018-4096 primarily focus on immediate software updates from Apple, which address the underlying memory corruption issues through patched WebKit components. System administrators should prioritize deployment of the relevant security updates for iOS 11.2.5, macOS 10.13.3, Safari 11.0.3, and other affected versions. Additionally, network-level protections such as web application firewalls and content filtering systems can help reduce exposure by blocking access to known malicious domains. Organizations should implement network segmentation to limit the potential impact of successful exploitation and maintain comprehensive monitoring for suspicious network activity. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and maps to ATT&CK technique T1059.007 for JavaScript execution, highlighting the need for both defensive measures and behavioral monitoring to detect potential exploitation attempts.