ClearanceKit is a macOS security tool that intercepts file-system access events and enforces per-process access policies to control file access. Prior to version 4.2.14, ClearanceKit contained two related startup defects that caused a critical delay in policy enforcement. Specifically, during the startup phase, only a single compile-time baseline rule was enforced by the underlying opfilter mechanism. All other managed file-access rules, including those delivered via Mobile Device Management (MDM) and user-defined policies, were not applied until the user interacted with the ClearanceKit GUI, which triggered a policy mutation over the XPC interprocess communication mechanism. This startup window effectively bypassed the intended fine-grained access controls, allowing processes to access files without the full policy enforcement. The vulnerability is classified under CWE-269 (Improper Privilege Management) because the system fails to enforce the correct privileges during initialization. The CVSS 4.0 base score is 6.3 (medium severity), reflecting local attack vector, low complexity, no privileges or user interaction required, but with a high scope and impact on system integrity and confidentiality. No known exploits are currently reported in the wild. The issue was addressed and patched in ClearanceKit version 4.2.14 by ensuring all policies are enforced immediately upon startup without requiring user interaction.

This vulnerability can lead to unauthorized file access on macOS systems running ClearanceKit versions prior to 4.2.14. During the startup window, processes may bypass critical file access restrictions, potentially exposing sensitive data or allowing unauthorized modification of files. This undermines the confidentiality and integrity of protected files and could facilitate privilege escalation or data leakage. Organizations relying on ClearanceKit for endpoint security or compliance enforcement may face increased risk of insider threats or malware exploiting this window to access restricted files. Although exploitation requires local access, the lack of user interaction or authentication makes it easier for malicious local users or malware to exploit. The impact is particularly significant in environments with strict data access policies, such as enterprises, government agencies, and regulated industries using MDM solutions to enforce security controls on macOS endpoints.

The primary mitigation is to upgrade ClearanceKit to version 4.2.14 or later, where the startup defects have been fixed to enforce all file-access policies immediately. Until the upgrade is applied, organizations should consider the following additional measures: restrict local access to macOS endpoints running vulnerable versions, monitor for unusual file access patterns during system startup, and limit the use of ClearanceKit on systems where strict file access control is critical. Administrators should also audit and verify that MDM-delivered policies are correctly applied after system boot. If upgrading is not immediately feasible, temporarily disabling ClearanceKit or replacing it with alternative file access control solutions may be necessary to avoid the risk window. Finally, ensure endpoint security monitoring tools are configured to detect suspicious behavior that could exploit this vulnerability.