CVE-2018-4161 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-2018-4161 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 core web browsing component responsible for rendering web content across Apple's ecosystem, making it a significant threat vector for remote code execution and system compromise. The vulnerability specifically impacts iOS versions prior to 11.3, Safari versions before 11.1, iCloud versions before 7.4 on Windows, iTunes versions before 12.7.4 on Windows, tvOS versions before 11.3, and watchOS versions before 4.3, demonstrating the widespread nature of the flaw across Apple's product portfolio. The WebKit component serves as the foundation for web content rendering in Apple's browsers and applications, making this vulnerability particularly dangerous as it could be exploited through any web-based attack vector.
The technical implementation of this vulnerability stems from improper memory handling within the WebKit engine that occurs when processing maliciously crafted web content. Attackers can leverage this flaw by hosting specially designed web pages that trigger memory corruption conditions during normal web browsing operations. The memory corruption can manifest in various forms including heap corruption, stack overflow conditions, or use-after-free scenarios that ultimately lead to arbitrary code execution or application crashes. This type of vulnerability typically falls under CWE-125, which describes "Out-of-bounds Read" conditions, or CWE-787, "Out-of-bounds Write," depending on the specific memory manipulation technique employed by the exploit. The flaw operates at the browser engine level, meaning that successful exploitation could potentially bypass operating system security mechanisms and provide attackers with elevated privileges within the application context.
The operational impact of CVE-2018-4161 extends beyond simple application instability to encompass serious security risks including remote code execution capabilities that could enable full system compromise. When exploited, this vulnerability allows attackers to execute arbitrary code on affected systems without requiring local user interaction, making it particularly dangerous for enterprise environments and individual users alike. The potential for denial of service attacks means that legitimate users could experience application crashes or system instability, while the remote execution capability opens pathways for more sophisticated attacks such as data exfiltration, persistence mechanisms, or lateral movement within networks. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1203, "Exploitation for Client Execution," as it enables remote attackers to gain code execution through web-based attack vectors without requiring physical access or complex local privilege escalation techniques.
Mitigation strategies for this vulnerability require immediate patch deployment across all affected Apple products and systems. Organizations should prioritize updating iOS devices to version 11.3 or later, Safari browsers to version 11.1 or later, iCloud on Windows to version 7.4 or later, iTunes on Windows to version 12.7.4 or later, tvOS to version 11.3 or later, and watchOS to version 4.3 or later. Network administrators should implement web filtering solutions to block access to known malicious domains and consider deploying intrusion detection systems to monitor for exploitation attempts. The vulnerability's nature suggests that users should exercise caution when visiting untrusted websites and avoid clicking on suspicious links or downloading content from unknown sources. Additionally, security teams should monitor for indicators of compromise related to this vulnerability and consider implementing application whitelisting policies to restrict execution of potentially malicious code. Regular security assessments and vulnerability scanning should be conducted to ensure that all affected systems remain properly patched and that no unauthorized access has occurred through exploitation of this flaw.