CVE-2018-4194 in macOS
Summary
by MITRE
In iOS before 11.4, iCloud for Windows before 7.5, watchOS before 4.3.1, iTunes before 12.7.5 for Windows, and macOS High Sierra before 10.13.5, an out-of-bounds read was addressed with improved input validation.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/28/2020
This vulnerability represents a classic out-of-bounds read flaw that affected multiple Apple platforms including iOS, watchOS, macOS, and iTunes applications. The issue stems from insufficient input validation mechanisms that failed to properly check array boundaries during data processing operations. Such vulnerabilities typically arise when developers assume input data will conform to expected parameters without adequate sanitization or boundary checking. The vulnerability is categorized under CWE-129 as an improper validation of array index, which directly leads to memory access violations when attempting to read data beyond allocated buffer limits.
The technical implementation of this flaw allowed attackers to manipulate input data in ways that would cause the applications to access memory locations outside their intended boundaries. This type of vulnerability can potentially lead to information disclosure, application crashes, or in more severe cases, arbitrary code execution depending on the specific memory corruption patterns. The affected versions represent a broad range of Apple's ecosystem where the same underlying code paths were susceptible to similar input validation weaknesses. The out-of-bounds read could occur during various operations involving data parsing, file handling, or network communication processes that process user-supplied or external input.
The operational impact of this vulnerability extends across multiple attack vectors within Apple's ecosystem, particularly affecting cloud synchronization services and file management operations. When exploited, the vulnerability could enable attackers to extract sensitive information from memory locations, potentially including authentication tokens, personal data, or system configuration details. The cross-platform nature of the vulnerability means that attackers could leverage similar exploitation techniques across different Apple products, making it particularly concerning for users with multiple devices. This type of vulnerability falls under ATT&CK technique T1059 where adversaries might attempt to execute malicious code through legitimate system processes, though the specific exploitation requires careful crafting of input data to trigger the memory access violation.
Apple addressed this vulnerability through improved input validation mechanisms that enforce stricter boundary checking on array operations and data processing routines. The security patches implemented in iOS 11.4, watchOS 4.3.1, macOS High Sierra 10.13.5, and iTunes 12.7.5 introduced enhanced validation protocols that verify array indices before memory access operations occur. These updates represent a defensive programming approach that aligns with secure coding standards and practices recommended by organizations such as the CERT/CC and OWASP. The fix demonstrates the importance of input validation as a fundamental security control that prevents numerous classes of memory corruption vulnerabilities. Organizations should prioritize applying these patches across all affected platforms to ensure comprehensive protection against potential exploitation attempts that could leverage this out-of-bounds read vulnerability.