CVE-2019-8730 in macOS
Summary
by MITRE
The contents of locked notes sometimes appeared in search results. This issue was addressed with improved data cleanup. This issue is fixed in macOS Catalina 10.15. A local user may be able to view a user?s locked notes.
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Analysis
by VulDB Data Team • 03/15/2024
The vulnerability described in CVE-2019-8730 represents a significant information disclosure flaw within macOS Catalina 10.15 that compromised the confidentiality of user data stored in locked notes applications. This issue specifically affected the search functionality of the operating system's note-taking applications, where locked notes were inadvertently exposed through search results despite being protected by user authentication mechanisms. The flaw demonstrates a failure in proper data isolation and access control enforcement within the system's note management subsystem, creating a scenario where sensitive user information could be accessed without proper authorization.
The technical root cause of this vulnerability stems from inadequate data cleanup processes that occurred during the search indexing and retrieval operations. When users locked their notes, the system should have ensured complete removal of those notes from searchable indexes and memory buffers, but instead retained fragments or complete entries that could be accessed through search queries. This represents a classic case of improper data sanitization and memory management, where the system failed to properly handle the transition state between locked and unlocked data. The vulnerability falls under the CWE category of improper data handling during access control enforcement, specifically CWE-200 for exposure of sensitive information and CWE-284 for improper access control mechanisms.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally undermines the trust model of the operating system's security architecture. A local attacker with access to a user's account could exploit this weakness to discover and retrieve sensitive information that was intended to be protected by the locking mechanism. This could include personal communications, financial information, private documents, or any other data that users reasonably expect to be secure when notes are locked. The vulnerability particularly affects users who store confidential information in their note applications, as it creates a persistent exposure that remains even after notes are locked, violating the principle of least privilege and proper access control enforcement.
The fix implemented by Apple in macOS Catalina 10.15 addressed this vulnerability through enhanced data cleanup procedures that ensure proper sanitization of locked note contents from search indexes and memory buffers. This remediation aligns with the ATT&CK framework's mitigation strategies for credential access and privilege escalation techniques, specifically targeting the persistence and information gathering phases where attackers might exploit such flaws. The solution demonstrates the importance of proper data lifecycle management and access control enforcement, particularly in applications that handle sensitive user information. Organizations and users should consider this vulnerability as part of broader security hygiene practices, ensuring that all operating system updates are applied promptly to address such information disclosure risks. The fix also highlights the critical need for comprehensive testing of access control mechanisms, particularly in applications where data confidentiality is paramount and where users expect robust protection of their personal information.