CVE-2019-8667 in macOS
Summary
by MITRE
An inconsistent user interface issue was addressed with improved state management. This issue is fixed in macOS Mojave 10.14.6. The encryption status of a Time Machine backup may be incorrect.
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Analysis
by VulDB Data Team • 07/10/2020
The vulnerability identified as CVE-2019-8667 represents a user interface inconsistency flaw within macOS Mojave 10.14.6 that affects Time Machine backup encryption status reporting. This issue stems from inadequate state management within the system's graphical interface components, creating a disconnect between the actual encryption status of backup volumes and what is displayed to users. The problem manifests specifically in the Time Machine backup encryption monitoring functionality, where users may receive misleading information about whether their backups are properly encrypted. This inconsistency creates a potential security risk as users may believe their data is protected when it is not, or conversely, may think their backups are unencrypted when they are actually secure. The vulnerability falls under the broader category of user interface security flaws that can undermine user trust and security practices, as documented in CWE-691, which addresses insufficient state management in security-critical interfaces.
The technical root cause of this vulnerability lies in the improper synchronization between the underlying encryption status monitoring system and the user-facing interface elements that report this information. When Time Machine performs backup operations, the system should maintain consistent state information about encryption status across all interfaces and notifications. However, the flawed implementation allows for a race condition or state synchronization issue where the encryption status displayed to users does not accurately reflect the actual encryption state of the backup volume. This represents a failure in proper state management protocols and can be categorized under ATT&CK technique T1552.001, which deals with unencrypted communications and data exposure through interface inconsistencies. The flaw particularly affects the integrity of security information presented to users, potentially leading to misinformed security decisions and compromised data protection practices.
The operational impact of CVE-2019-8667 extends beyond simple user confusion to potentially serious security implications for macOS users relying on Time Machine backups. Users may unknowingly believe their backups are encrypted when they are not, leading to potential data exposure in case of unauthorized access to backup storage devices. Conversely, users might overestimate the security of their backups, leading to inadequate security measures in their overall data protection strategy. This inconsistency can undermine the trust users place in macOS security features and may result in delayed or ignored security updates. The vulnerability particularly affects enterprise environments where backup encryption is critical for compliance with data protection regulations and security policies. Organizations may experience increased risk of data breaches or regulatory violations if they rely on inaccurate encryption status reporting from Time Machine backups.
The fix for CVE-2019-8667 was implemented through improved state management mechanisms within macOS Mojave 10.14.6, addressing the synchronization issues between encryption status monitoring and user interface reporting. This update ensures that the encryption status displayed to users accurately reflects the actual state of Time Machine backups. Organizations should prioritize updating to macOS Mojave 10.14.6 or later versions to resolve this vulnerability. System administrators should conduct thorough testing of backup operations after applying the update to verify that encryption status reporting functions correctly. Additional mitigations include implementing redundant backup verification procedures and maintaining awareness of potential interface inconsistencies in other security-related applications. The vulnerability highlights the importance of proper state management in security interfaces and serves as a reminder that user-facing security information must be accurate and reliable to maintain effective security postures. Regular security audits should include verification of interface consistency and state management across all security-critical applications to prevent similar issues from arising.