ClearanceKit intercepts file‑system access events on macOS and enforces per‑process access policies. Prior to version 5.0.10, each table in the on‑disk SQLite policy store at /Library/Application Support/clearancekit/store.db is verified using an ECDSA signature stored in the data_signatures table. The signed payload contains only the canonical row content, with no version counter or freshness binding. An attacker who can write store.db and the matching data_signatures row — feasible during the opfilter‑update window when the Endpoint Security filter is offline, or via offline‑boot / decrypted‑backup scenarios — can substitute a previously‑captured legitimately‑signed snapshot. opfilter accepts the older snapshot as fully valid on next boot because the existing signatures still verify, enabling the attacker to recover arbitrary access privileges in the process sandbox. The weakness is identified as CWE‑294, a failure to enforce proper signature freshness checks.

The issue affects installations of ClearanceKit from the craigjbass vendor prior to version 5.0.10. Systems running any earlier secure‑file‑system monitoring setup that uses ClearanceKit’s SQLite store located at "/Library/Application Support/clearancekit/store.db" are vulnerable. No newer versions include a fix.

The CVSS score of 6.9 denotes a moderate severity but the exploit requires the attacker to write to the policy database, a privilege that is typically available only during the Endpoint Security filter offline window or via offline boot or decrypted backup scenarios. The EPSS score of less than 1% indicates a very low but non‑zero probability of exploitation in the wild. ClearanceKit is not listed in CISA’s KEV catalog, suggesting that no widespread, active exploits have been reported. Still, the risk is significant for environments where the endpoint security filter can be taken offline or where backups are accessible in decrypted form.