CVE-2018-4296 in macOS
Summary
by MITRE • 10/28/2020
This issue is fixed in macOS Mojave 10.14. A permissions issue existed in DiskArbitration. This was addressed with additional ownership checks.
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Analysis
by VulDB Data Team • 11/27/2020
The vulnerability identified as CVE-2018-4296 represents a critical permissions flaw within the DiskArbitration framework of macOS operating systems. This issue specifically affected versions prior to macOS Mojave 10.14, where the DiskArbitration service failed to properly enforce ownership checks when managing disk operations. The vulnerability stems from insufficient validation of file and directory permissions during disk arbitration processes, creating potential attack vectors for malicious actors to escalate privileges or access restricted system resources.
The technical flaw manifests in the DiskArbitration subsystem which is responsible for managing disk operations and ensuring proper access controls when volumes are mounted or unmounted. This subsystem handles the arbitration of disk access requests and maintains the security boundaries that prevent unauthorized access to system resources. The vulnerability occurs when the system fails to verify proper ownership and permissions before allowing certain disk operations to proceed, potentially enabling local attackers to manipulate disk access controls and gain elevated privileges.
From an operational impact perspective, this vulnerability poses significant risks to macOS systems as it could allow attackers to bypass standard permission controls and potentially execute unauthorized operations on disk volumes. The flaw specifically affects the integrity of the disk arbitration process where proper ownership verification should occur but fails to do so. This could lead to privilege escalation scenarios where local users might be able to access files and directories they should not normally have access to, or manipulate disk operations in ways that could compromise system security and data integrity.
The remediation for this vulnerability involved implementing additional ownership checks within the DiskArbitration framework as part of the macOS Mojave 10.14 release. This update addressed the core issue by strengthening the permission validation mechanisms that govern disk access operations. The fix ensures that proper ownership verification occurs before allowing disk operations to proceed, thereby preventing unauthorized access patterns that could lead to privilege escalation or data exposure. Organizations should prioritize updating to macOS Mojave 10.14 or later versions to mitigate this vulnerability.
This vulnerability aligns with CWE-284 which describes improper access control issues in software systems. The flaw demonstrates how insufficient access control mechanisms in system-level components can create security risks that affect the entire operating system. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques where attackers could leverage weak permission controls to gain elevated system privileges. The vulnerability also intersects with defense evasion tactics as the compromised access controls could enable attackers to bypass normal security boundaries and maintain persistent access to system resources. Organizations should implement proper patch management processes to ensure timely deployment of security updates addressing this class of vulnerabilities in their macOS environments.