BSI C5:2020 BCM-04 — Verification, updating and testing of the business continuity

What this control requires

Annually reviews and tests continuity plans, involving customers and third parties. Documents results to improve measures, ensuring robust recovery capabilities to protect cloud customer data and maintain service availability.

In plain English

Annually reviews and tests continuity plans, involving customers and third parties. In practice, this means you can prove you risk measures-level controls on a defined cadence.

Why it matters

BSI C5 is the default cloud-security baseline German public-sector buyers and many DAX-listed enterprises expect; gaps here directly block procurement in the DACH region and frequently appear as must-have items in EU public-tender documents.

This control is rated high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

What an auditor looks for

A C5 attesting auditor (under ISAE 3000 / IDW PS 860) tests both the design and — for a Type 2 — the operating effectiveness over the attestation period. For each criterion they look for both the Basic and any in-scope Additional objectives.

Within Business Continuity Management, the assessor will trace your implementation back to the catalogue reference (Criterion BCM-04) and look for objective evidence on the latest two assessment cycles.

How to implement

Business Continuity

BC/DR. Define RTO/RPO per service, test backup restoration quarterly, and run a tabletop of full-region failover annually.

Backups. Immutable backups (S3 Object Lock / Azure immutable storage / GCS bucket lock) plus an air-gapped copy for ransomware resilience.

Cloud Posture

CSPM. Run Wiz / Prisma / Defender for Cloud / Security Command Center over every account; auto-ticket findings above your accepted-risk threshold.

Code Review Testing

Pipeline. Require at least one human reviewer plus passing CI (lint, type, unit, security scan) before merge — protected branches enforce this.

Operational checklist

• Risk. Document the trigger, the owner and the cadence.
• Review. Document the trigger, the owner and the cadence.
• Verification. Document the trigger, the owner and the cadence.
• Data. Document the trigger, the owner and the cadence.
• Business. Document the trigger, the owner and the cadence.
• Scope: measures, cloud customer data, business continuity, management.

Evidence to collect

• Policy Document. A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Verification, updating and testing of the business continuity.

Common pitfalls

• DR plans that have never been tested in earnest, or that depend on an MFA token only one person can produce.
• Treating CSPM findings as a backlog instead of a hot queue: findings older than the policy SLA accumulate until the auditor asks why.

Related controls in BSI C5:2020

• Criterion BCM-03 — Planning business continuity
• Criterion BCM-02 — Business impact analysis policies and instructions
• Criterion BCM-01 — Top management responsibility
• Criterion OPS-07 — Data Backup and Recovery - Monitoring
• Criterion OPS-01 — Capacity Management - Planning
• Criterion OPS-19 — Managing Vulnerabilities, Malfunctions and Errors - Penetration Tests

References

• Bundesamt für Sicherheit in der Informationstechnik (BSI) — BSI C5:2020
• Catalogue identifier: Criterion BCM-04

Topics: governance riskbusiness continuitybackup recoverycloud posturecode review testing