A.8.17 Technological
Clock synchronization
Structured attributes from ISO/IEC 27002:2022 — control type · CIA properties · cybersecurity concept · operational capability · security domain. What do these mean?
Mapped NIST 800-53 r5 controls (10)
Our AI-authored reading (authority llm_unverified, under review) of how this ISO control and each NIST 800-53 control relate. Not an ISO or NIST product.
Direction: ← other covers this;
→ this covers other (F/M/P = full / mostly /
partial). gov = governs / implements (a mandate, not coverage).
Why these map — AI rationale (under review)
- AU-8fullcovers — Both controls establish a single authoritative time source and enforce synchronization across systems so that audit and event records carry consistent, reliable timestamps.
- SC-45mostlyaligns with — The ISO requirement to synchronize all systems to a trusted reference clock directly supports the NIST objective of maintaining accurate system time across the enterprise.
- SC-45mostlycovers — A.8.17's purpose-built requirement for clock synchronization to enable event correlation and incident analysis accounts for the bulk of SC-45's functional mandate; a residual of SC-45's intra- and inter-component technical synchronization details (e.g., protocols, tolerance values) sits outside the ISO control's explicit scope.
- AU-12partialaligns with — Accurate, synchronized clocks are a prerequisite for generating comparable and trustworthy audit records, which AU-12 relies upon.
- AU-6partialaligns with — Reliable timestamps produced by clock synchronization enable effective correlation and review of audit records during analysis and reporting activities.
Aligned NIST CSF 2.0 outcomes (15)
NIST CSF 2.0 outcomes this ISO control aligns with — our AI-authored analysis (authority llm_unverified, under review).
Direction: ← other covers this;
→ this covers other (F/M/P = full / mostly /
partial). gov = governs / implements (a mandate, not coverage).
Why these map — AI rationale (under review)
- PR.PS-04mostlyaligns with — Synchronized, accurate time sources are a prerequisite for generating reliable log records that can be used for continuous monitoring and later analysis.
- DE.AE-02partialaligns with — Reliable time-stamps allow analysts to reconstruct the sequence and timing of activities associated with potentially adverse events.
- DE.AE-03partialaligns with — Consistent timestamps across systems enable correlation of event data from multiple sources during adverse-event analysis.
- GV.OC-03partialaligns with — Documenting and meeting external legal, regulatory, and contractual requirements for accurate time representation directly supports compliance obligations.
- ID.RA-07partialaligns with — Tracking clock variance between cloud and on-premises environments provides a measurable input for assessing risk impact of configuration changes or exceptions.
- DE.AE-02implements — A.8.17 directly operationalizes accurate timestamping required for event correlation and analysis that DE.AE-02 names; the link is within the shared detection/analysis domain but the outcome does not cite clock sync explicitly.
- DE.AE-03implements — A.8.17 directly operationalizes synchronized clocks so that events from multiple sources can be reliably correlated, which is the exact outcome DE.AE-03 names; the link is within the detection-analysis domain but not by explicit citation of correlation mechanics.
- GV.OC-03implements — Assessed as NOT holding by the authoring instrument at v1.22-2026-08-29. This row records a tested non-relation; it is not a graded claim and carries no rationale, because the instrument produced none when the verb did not hold.
- ID.RA-07implements — Assessed as NOT holding by the authoring instrument at v1.22-2026-08-29. This row records a tested non-relation; it is not a graded claim and carries no rationale, because the instrument produced none when the verb did not hold.
- PR.PS-04implements — A.8.17 directly operationalizes synchronized clocks so that the generated log records required by PR.PS-04 can be reliably correlated and analyzed in continuous monitoring
Related OWASP ASVS 5.0 requirements (3)
Application-security verification requirements (OWASP ASVS 5.0) this ISO control aligns with; links open the ASVS chapter. Our AI-authored analysis (authority llm_unverified, under review) — many ISO controls have no ASVS counterpart.
Direction: ← other covers this;
→ this covers other (F/M/P = full / mostly /
partial). gov = governs / implements (a mandate, not coverage).
Why these map — AI rationale (under review)
- V16.2.2fullaligns with — Both require synchronized, trusted time sources so that security event timestamps remain accurate and comparable across systems for investigation and correlation.
- V16.2.1partialaligns with — Reliable clock synchronization underpins the completeness and accuracy of the metadata (when, where, who, what) that must be captured in each log entry.
Related weaknesses / CWE (2)
Weakness classes this ISO control helps prevent or mitigate — our AI-authored analysis (authority llm_unverified, under review).
Direction: ← other covers this;
→ this covers other (F/M/P = full / mostly /
partial). gov = governs / implements (a mandate, not coverage).
Why these map — AI rationale (under review)
- CWE-778mitigates — Trustworthy timestamps ensure that security-relevant events are recorded with accurate chronology, improving the usefulness of logs for detecting and investigating incidents.
Mitigated MITRE ATT&CK techniques (81)
Adversary techniques (MITRE ATT&CK Enterprise) this ISO control helps mitigate; links open attack.mitre.org. Our AI-authored analysis (authority llm_unverified, under review).
Direction: ← other covers this;
→ this covers other (F/M/P = full / mostly /
partial). gov = governs / implements (a mandate, not coverage).
Why these map — AI rationale (under review)
- T1078detects — A.8.17 ensures accurate, synchronized timestamps across systems (including logs from cloud/on-prem, building/entry systems) to enable correlation and analysis of security events and support incident investigations, which surfaces anomalous account usage in logs but does not itself monitor for or identify the T1078 technique.
- T1546.003detects — A.8.17 requires monitoring clock differences across services (including cloud) to detect discrepancies that could hinder event correlation, which surfaces anomalies in time-based WMI event subscriptions but does not broadly instrument or detect the technique's installation or execution.
- T1578.004detects — A.8.17 requires monitoring clock differences across cloud/on-prem services to mitigate discrepancy risks, which can surface anomalous time jumps or resets that occur during a snapshot revert, but this is indirect, limited to time artifacts, and depends on scope rather than directly targeting the revert action itself.
- T1685.002detects — A.8.17 requires monitoring clock differences across cloud/on-prem services to record discrepancies that could affect log correlation, which surfaces anomalies in logging configuration or tampering as part of supporting incident investigations, but this is a narrow slice of the broad technique of disabling/modifying cloud logging mechanisms.
Prevented OWASP Web Top 10 (2025) risks (3)
OWASP Web Top 10 (2025) risk categories this ISO control helps prevent or mitigate — our AI-authored analysis (authority llm_unverified, under review).
Direction: ← other covers this;
→ this covers other (F/M/P = full / mostly /
partial). gov = governs / implements (a mandate, not coverage).
Why these map — AI rationale (under review)
- A09mitigates — A.8.17 ensures accurate, synchronized timestamps on logs (and records discrepancies across cloud/on-prem), which bounds the consequence of missing or un-correlatable logs by making whatever events *are* captured usable for detection and investigation; it does not cause alerts to fire or protect log integrity.
Control IDs, short titles and the structured attribute table (control type, CIA properties, cybersecurity-concept, operational capability, security domain) are facts from ISO/IEC 27001:2022 Annex A / ISO/IEC 27002:2022. The full implementation guidance prose lives in ISO/IEC 27002:2022 — not reproduced here. Cross-walks to NIST 800-53, NIST CSF 2.0, OWASP ASVS, CWE, MITRE ATT&CK and OWASP Web Top 10 are our own AI-authored analysis (authority llm_unverified, under review), not an ISO, NIST, MITRE or OWASP product — how ours compare.