CVE-2018-4346 in macOS
Summary
by MITRE
A validation issue existed which allowed local file access. This was addressed with input sanitization. This issue affected versions prior to macOS Mojave 10.14.
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Analysis
by VulDB Data Team • 04/08/2020
The vulnerability identified as CVE-2018-4346 represents a critical local file access issue that existed within macOS systems prior to the release of macOS Mojave 10.14. This flaw originated from inadequate input validation mechanisms that failed to properly sanitize user-supplied data before processing. The vulnerability allowed malicious actors with local system access to exploit improper validation checks and gain unauthorized access to files that should have been protected by the operating system's security model. The issue specifically affected the way the system handled file path inputs and directory traversal operations, creating potential pathways for attackers to access sensitive system files, user data, and configuration resources that were not intended to be accessible through normal system operations.
The technical implementation of this vulnerability falls under the category of improper input validation, which maps to CWE-20 - Improper Input Validation as defined by the Common Weakness Enumeration standard. This weakness occurs when a system fails to validate or sanitize input data properly, allowing malicious inputs to be processed without adequate security checks. The vulnerability was particularly concerning because it existed at the operating system level, providing attackers with direct access to the file system without requiring elevated privileges beyond local user access. Attackers could potentially exploit this weakness to read system configuration files, access user documents, examine application data, or even retrieve sensitive information stored in protected directories.
The operational impact of CVE-2018-4346 extended beyond simple file access violations, as it represented a fundamental breakdown in the operating system's security boundaries. Local file access vulnerabilities of this nature can serve as a stepping stone for more sophisticated attacks, allowing threat actors to gather intelligence about the system's configuration, identify potential privilege escalation opportunities, or extract sensitive data that could be used in subsequent phases of an attack. The vulnerability was particularly dangerous in environments where local access was not properly restricted or where users had legitimate access to multiple system resources. The issue affected all macOS versions prior to 10.14, meaning that organizations running older systems were exposed to this risk and could potentially be compromised through this specific vector.
The remediation for this vulnerability involved implementing comprehensive input sanitization measures that addressed the root cause of the validation issue. Apple's fix included strengthening the validation checks for file path inputs and ensuring that all user-supplied data was properly sanitized before being processed by system functions. This approach aligns with the ATT&CK framework's concept of privilege escalation through input validation failures, where attackers exploit improper validation to gain unauthorized access to system resources. Organizations should have implemented immediate updates to macOS 10.14 or later versions to address this vulnerability, as the fix required changes at the kernel level and system libraries that handled file operations. The resolution also emphasized the importance of maintaining up-to-date operating systems and implementing proper security monitoring to detect potential exploitation attempts.
This vulnerability demonstrates the critical importance of input validation in operating system security and serves as a reminder of how seemingly simple validation flaws can create significant security risks. The issue highlights the need for comprehensive security testing, particularly around file system operations and input handling mechanisms. Organizations should have implemented proper patch management procedures to ensure timely deployment of security updates and maintained awareness of potential exploitation vectors that could leverage similar validation weaknesses in other system components. The vulnerability also underscores the importance of least privilege principles and proper access controls, as local access combined with validation flaws creates opportunities for attackers to escalate their access and compromise system integrity.