CVE-2018-4142 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.3 is affected. macOS before 10.13.4 is affected. tvOS before 11.3 is affected. watchOS before 4.3 is affected. The issue involves the "CoreText" component. It allows remote attackers to cause a denial of service (application crash) via a crafted string.
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Analysis
by VulDB Data Team • 02/26/2023
The vulnerability identified as CVE-2018-4142 represents a significant security flaw within Apple's CoreText framework that affected multiple operating systems including iOS, macOS, tvOS, and watchOS. This issue stems from improper handling of crafted strings within the text rendering component that forms part of Apple's core system libraries. The vulnerability specifically impacts versions prior to iOS 11.3, macOS 10.13.4, tvOS 11.3, and watchOS 4.3, indicating a widespread exposure across Apple's ecosystem. CoreText serves as a fundamental text rendering engine responsible for processing and displaying text across various Apple applications and system components, making this vulnerability particularly concerning from a security perspective.
The technical nature of this vulnerability involves a buffer overflow or memory corruption issue within the CoreText processing pipeline when handling specially crafted strings. Attackers can exploit this weakness by constructing malicious text input that, when processed by the CoreText framework, triggers an application crash or system instability. This type of vulnerability falls under CWE-121, which describes "Stack-based Buffer Overflow" or similar memory corruption categories, though the specific implementation likely involves heap-based memory issues given the nature of text processing components. The vulnerability demonstrates how text parsing components can become attack vectors when proper input validation and bounds checking mechanisms are insufficient.
From an operational standpoint, this vulnerability presents a remote denial of service threat that could be exploited by attackers to disrupt normal system operations across Apple devices. The impact extends beyond simple application crashes to potentially affecting system stability and user experience, particularly in environments where text processing is frequent or automated. The vulnerability's remote exploitability means that attackers do not require physical access to devices or local network privileges to cause disruption. This characteristic aligns with ATT&CK technique T1499.004, which covers "Endpoint Denial of Service" through remote exploitation of software vulnerabilities. The widespread nature of the affected platforms increases the potential attack surface significantly.
The remediation for this vulnerability required Apple to release system updates that patched the CoreText component's string handling mechanisms. Users were advised to update their systems to versions that included fixed implementations of the text rendering engine. Organizations should implement comprehensive patch management processes to ensure all affected Apple devices receive timely updates. Security teams should monitor for any potential exploitation attempts and consider network-level monitoring to detect unusual text processing patterns that might indicate exploitation attempts. The vulnerability highlights the importance of regular security updates and proper input validation in system components that handle user-provided data, particularly those involved in text rendering and processing functions.