Cyber Resilience

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: 22 August 2026 14:14 UTC

Implementations targeting this control (0)

ATT&CK techniques this control mitigates (0)

Weaknesses this control addresses (8)AI-assisted

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 Authorization10,200+Always invoking the reference monitor prevents missing authorization checks for protected resources.
CWE-284Improper Access Control6,900+Provides a tamperproof, always-invoked, and verifiable mechanism to enforce access control policies.
CWE-863Incorrect Authorization3,900+The small, testable reference monitor reduces the likelihood of incorrect authorization implementations.
CWE-269Improper Privilege Management3,400+Enforces proper privilege management by requiring all decisions through the verified reference monitor.
CWE-306Missing Authentication for Critical Function3,300+Guarantees critical functions are protected by mandatory invocation of the access control mechanism.
CWE-285Improper Authorization1,500+Ensures authorization decisions are always performed by a complete and analyzable reference monitor.
CWE-693Protection Mechanism Failure700+Implements a reliable, tamperproof protection mechanism whose completeness can be assured.
CWE-425Direct Request ('Forced Browsing')200+Forces 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-2024-1709 KEV 10.010.00.9996good
CVE-2024-27198 KEV 9.99.80.9994good
CVE-2024-10924 9.99.80.8203good
CVE-2024-55591 KEV 9.99.80.9826good
CVE-2025-2746 KEV 9.99.80.5905good
CVE-2025-2747 KEV 9.99.80.9238good
CVE-2024-56325 9.99.80.7867good
CVE-2025-57819 KEV 9.99.80.8827good
CVE-2026-23760 KEV 9.99.80.9627good
CVE-2026-24858 KEV 9.99.80.8584good
CVE-2024-23917 9.49.80.5373good
CVE-2024-7314 9.49.80.5147good
CVE-2024-50379 9.29.80.4431good
CVE-2025-22224 KEV 9.29.30.0156good
CVE-2024-10081 9.110.00.3912good
CVE-2022-25369 9.19.80.4074good
CVE-2026-20079 9.110.00.3767good
CVE-2026-10523 9.09.90.5187good
CVE-2024-33610 8.89.10.4584good
CVE-2026-1603 KEV 8.88.60.8056good
CVE-2025-24472 KEV 8.78.10.0358good
CVE-2026-18577 KEV8.78.10.0410good
CVE-2024-39309 8.59.80.2017good
CVE-2025-34026 KEV 8.57.50.8194good
CVE-2025-38352 KEV 8.57.80.0128good

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