# BSI C5:2020 SSO-01 — Policies and instructions for controlling and monitoring third parties - Source: https://support.icompaas.com/compliance/bsi-c5-2020/sso-01-policies-and-instructions-for-controlling-and-monitoring-third-parties - Section: [Compliance](https://support.icompaas.com/compliance) › [BSI C5:2020 (Cloud Computing Compliance Criteria)](https://support.icompaas.com/compliance/bsi-c5-2020) › Supplier & Service Oversight (SSO) - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **BSI C5:2020**·Criterion `SSO-01`·high·Component: **Supplier & Service Oversight** ## What this control requires > Documents policies per SP-01 for third-party oversight, specifying risk assessment, security requirements, and monitoring. Ensures subcontractors comply with standards, protecting cloud customer data processed by external service providers. > > — BSI C5:2020, Criterion SSO-01 ### In plain English Documents policies per SP-01 for third-party oversight, specifying risk assessment, security requirements, and monitoring. In practice, this means you can prove you risk cloud customer data-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 **Supplier & Service Oversight**, the assessor will trace your implementation back to the catalogue reference (Criterion SSO-01) and look for objective evidence on the latest two assessment cycles. ## How to implement #### Cloud Posture **CSPM.** Run Wiz / Prisma / Defender for Cloud / Security Command Center over every account; auto-ticket findings above your accepted-risk threshold. ### Operational checklist - **Risk.** Document the trigger, the owner and the cadence. - **Security.** Document the trigger, the owner and the cadence. - **Data.** Document the trigger, the owner and the cadence. - **Scope:** cloud customer data, management. ## Evidence to collect - **Vendor Risk Management.** `vendor_risk_management` evidence - **Policy Document.** A signed and version-controlled policy / standard / procedure document. Third-party risk management evidence (assessments, contracts, due diligence) shows supplier oversight. Signed policy or standard documents the safeguard. Focus: Policies and instructions for controlling and monitoring third parties. ## Common pitfalls - Treating CSPM findings as a backlog instead of a hot queue: findings older than the policy SLA accumulate until the auditor asks why. ## How it maps to other frameworks Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit. - [**CIS Controls v8 3.8** — Document Data Flows](https://support.icompaas.com/compliance/cis-controls-v8/3-8-document-data-flows) - [**ISO/IEC 27001:2022 A.5.19** — Information security in supplier relationships](https://support.icompaas.com/compliance/iso-27001-2022/a-5-19-information-security-in-supplier-relationships) - [**SOC 2 (2017 TSC) CC9.2** — Vendor Risk Management](https://support.icompaas.com/compliance/soc-2-trust-services-criteria/cc9-2-vendor-risk-management) - [**ISO/IEC 27701:2025 A.3.10** — Supplier agreements](https://support.icompaas.com/compliance/iso-27701-2025/a-3-10-supplier-agreements) - [**GDPR Article 28** — Processor](https://support.icompaas.com/compliance/gdpr/article-28-processor) ## Related controls in BSI C5:2020 - [**Criterion COS-03** — Monitoring of connections in the Cloud Service Provider's network](https://support.icompaas.com/compliance/bsi-c5-2020/cos-03-monitoring-of-connections-in-the-cloud-service-provider-s-network) - [**Criterion SSO-02** — Risk assessment of service providers and suppliers](https://support.icompaas.com/compliance/bsi-c5-2020/sso-02-risk-assessment-of-service-providers-and-suppliers) - [**Criterion SSO-03** — Directory of service providers and suppliers](https://support.icompaas.com/compliance/bsi-c5-2020/sso-03-directory-of-service-providers-and-suppliers) - [**Criterion SSO-04** — Monitoring of compliance with requirements](https://support.icompaas.com/compliance/bsi-c5-2020/sso-04-monitoring-of-compliance-with-requirements) - [**Criterion SSO-05** — Exit strategy for the receipt of benefits](https://support.icompaas.com/compliance/bsi-c5-2020/sso-05-exit-strategy-for-the-receipt-of-benefits) - [**Criterion OIS-07** — Application of the Risk Management Policy](https://support.icompaas.com/compliance/bsi-c5-2020/ois-07-application-of-the-risk-management-policy) ## References - [Bundesamt für Sicherheit in der Informationstechnik (BSI) — BSI C5:2020](https://www.bsi.bund.de/EN/Topics/CloudComputing/Compliance_Criteria_Catalogue/Compliance_Criteria_Catalogue_node.html) - Catalogue identifier: `Criterion SSO-01` Topics: governance riskvendor riskvendor managementsupply chain securitycloud posturecontinuous monitoring ## Related compliance guidance - [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them. - [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.