Cyber Posture

NIST 800-53 r5 · Controls catalogue · Family AC

AC-25Reference Monitor

Implement a reference monitor for {{ insert: param, ac-25_odp }} that is tamperproof, always invoked, and small enough to be subject to analysis and testing, the completeness of which can be assured.

Last updated: 09 May 2026 03:25 UTC

Implementations targeting this control (0)

ATT&CK techniques this control mitigates (0)

Weaknesses this control addresses (8)AI

CWEs ranked by how often they appear in real CVEs. The rationale describes how this control reduces exploitability of each weakness class.

CWE Name CVEs Why this control addresses it
CWE-862Missing Authorization8,680Always invoking the reference monitor prevents missing authorization checks for protected resources.
CWE-284Improper Access Control4,832Provides a tamperproof, always-invoked, and verifiable mechanism to enforce access control policies.
CWE-863Incorrect Authorization3,234The small, testable reference monitor reduces the likelihood of incorrect authorization implementations.
CWE-269Improper Privilege Management2,907Enforces proper privilege management by requiring all decisions through the verified reference monitor.
CWE-306Missing Authentication for Critical Function2,567Guarantees critical functions are protected by mandatory invocation of the access control mechanism.
CWE-285Improper Authorization1,230Ensures authorization decisions are always performed by a complete and analyzable reference monitor.
CWE-693Protection Mechanism Failure476Implements a reliable, tamperproof protection mechanism whose completeness can be assured.
CWE-425Direct Request ('Forced Browsing')255Forces all accesses through the reference monitor, preventing direct or forced requests that bypass checks.

Top CVEs where this control is the strongest mitigation

CVE Risk CVSS EPSS Match
CVE-2025-241782.09.80.0067good
CVE-2025-432612.09.80.0025good
CVE-2026-356661.88.80.0005good
CVE-2026-296481.88.80.0004good
CVE-2026-336311.78.70.0002good
CVE-2026-242221.78.60.0006good
CVE-2025-03591.78.50.0011good
CVE-2026-355701.78.40.0001good
CVE-2026-00081.78.40.0001good
CVE-2026-412961.68.20.0003good
CVE-2026-288171.68.10.0001good
CVE-2025-255001.67.50.0092good
CVE-2026-336321.67.80.0001good
CVE-2025-697831.67.80.0001good
CVE-2024-538411.67.80.0001good
CVE-2026-375251.67.80.0001good
CVE-2026-239891.68.20.0002good
CVE-2025-359981.67.90.0001good
CVE-2026-329881.57.50.0001good
CVE-2026-409680.84.20.0003good
CVE-2025-712572.47.30.1557good
CVE-2024-559682.48.80.1048good
CVE-2024-443732.19.80.0157good
CVE-2026-238302.010.00.0020good
CVE-2025-242382.09.80.0081good

Other controls in family AC

AC-1 AC-10 AC-11 AC-12 AC-13 AC-14 AC-15 AC-16 AC-17 AC-18 AC-19 AC-2 AC-20 AC-21 AC-22 AC-23 AC-24 AC-3 AC-4 AC-5 AC-6 AC-7 AC-8 AC-9