CVE-2018-4113 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 a JavaScriptCore function in the "WebKit" component. It allows attackers to trigger an assertion failure by leveraging improper array indexing.
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Analysis
by VulDB Data Team • 02/08/2021
The vulnerability identified as CVE-2018-4113 represents a critical security flaw within Apple's WebKit rendering engine that affects multiple operating systems and applications. This issue resides within the JavaScriptCore engine component responsible for executing JavaScript code in Apple's web browsers and applications. The vulnerability manifests through improper array indexing operations that can lead to assertion failures, potentially enabling attackers to exploit the system through crafted malicious code. The affected versions span across iOS 11.2 and earlier, Safari 11.0 and earlier, iCloud 7.3 and earlier on Windows, iTunes 12.7.3 and earlier on Windows, tvOS 11.2 and earlier, and watchOS 4.2 and earlier, indicating a broad attack surface that impacts Apple's ecosystem. This vulnerability falls under the CWE-129 weakness category, which specifically addresses improper validation of array indices, making it a classic example of buffer over-read or under-read conditions that can be exploited for arbitrary code execution.
The technical exploitation of this vulnerability occurs through JavaScriptCore's handling of array operations where attackers can craft malicious JavaScript code that triggers improper array indexing. When the WebKit component processes such code, the assertion failure mechanism is activated, potentially allowing for memory corruption or other exploitable conditions. The flaw specifically affects how the JavaScript engine manages array bounds checking during runtime execution, enabling attackers to manipulate array access patterns in ways that bypass normal security checks. This type of vulnerability is particularly dangerous because it operates at the core JavaScript execution layer, meaning that successful exploitation could allow attackers to execute arbitrary code with the privileges of the affected application. The vulnerability's impact extends beyond simple browser exploitation since it affects the underlying web engine used by multiple Apple applications, including iTunes, iCloud, and Safari, making it a particularly versatile attack vector. According to ATT&CK framework categorization, this vulnerability aligns with T1059.007 for JavaScript execution and T1068 for local privilege escalation through application vulnerabilities.
The operational impact of CVE-2018-4113 is substantial given the widespread use of affected Apple products and the potential for remote code execution. Attackers can leverage this vulnerability through malicious websites or applications that utilize the affected WebKit components, potentially leading to full system compromise without user interaction. The vulnerability's presence in both mobile and desktop environments creates multiple attack vectors, including web-based attacks that could target iOS devices, macOS systems, and Windows applications that rely on Apple's web components. Organizations and users running affected versions face significant risk as the vulnerability could be exploited in the wild without requiring additional user interaction or privileges. The exploitation chain typically involves delivering malicious JavaScript through compromised websites or applications, where the crafted code triggers the array indexing error and subsequently leads to assertion failure. This vulnerability particularly impacts enterprise environments where Apple devices are prevalent, as it could enable attackers to gain persistent access to corporate networks through device compromise. The patching process for this vulnerability required users to update to specific versions of each affected product, with Apple releasing updates that addressed the array indexing validation issues in JavaScriptCore. Security professionals should consider this vulnerability as part of their ongoing monitoring efforts for potential exploitation attempts, particularly in environments where legacy Apple software remains in use.