# BSI C5 SSO-01 — Policies and instructions for controlling and monitoring third parties

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_bsic5_sso01_66fa618454-bsi-c5-sso-01-policies-and-instructions-for-controlling-and-monitoring-third-parties
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [BSI C5 (German Cloud)](https://support.icompaas.com/support/solutions/c_gen_bsi_c5) › [Supplier & Service Oversight](https://support.icompaas.com/support/solutions/folders/f_gen_cgenbsic5_supplierserviceoversight)
- Last updated: 2026-05-30
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

BSI C5 · Control SSO-01 · Priority: high · Component: Supplier & Service Oversight

### What this control covers

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.

### Why it matters

Risk is the language an executive team understands; this control connects technical reality to board-level decisions and budget allocation.

### How to implement

#### AWS

Codify the policy intent as **SCPs, AWS Config conformance packs, and Security Hub standards** so the cloud enforces what the document says.

#### Azure

Codify in **Azure Policy initiatives** (built-in regulatory compliance for CIS, ISO 27001, SOC 2, HIPAA) and assign at management-group level.

#### GCP

**Org Policy Service** for guardrails and **Config Validator** in CI to pre-check Terraform plans against policy as code (Rego).

#### Google Workspace

Forward the **Admin, Login, Drive, Token and Mobile** audit logs to Cloud Logging (Workspace BigQuery export). Alert on impossible-travel logins, OAuth-scope grants for high-risk scopes, and external Drive sharing of sensitive labels.

#### GitHub

Stream the **Enterprise audit log** to your SIEM and enable **Audit Log API** alerting on key events: owner changes, IP allowlist edits, secret deletions, repo visibility flips.

#### On-premises

Maintain a policy library with a documented review cadence (annual minimum); store in your GRC tool with attestation tracking. Map each policy to controls so an audit pull cites the exact policy clause.

### Evidence to collect

-   `vendor_risk_management` — See the iCompaas Evidence library for the canonical source for this evidence type.
-   `policy_document` — A signed, version-controlled policy stating leadership intent and the named owner.

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.

### Quick checklist

-   Risk — Cloud Customer Data / Management
-   Security — Cloud Customer Data / Management
-   Data — Cloud Customer Data / Management

### Related articles on this site

-   [Microsoft Cloud Security Posture Management (CSPM)](https://support.icompaas.com/support/solutions/articles/62000234105-microsoft-cloud-security-posture-management-cspm-)
-   [Source Code Supply Chain Security](https://support.icompaas.com/support/solutions/articles/62000225179-source-code-supply-chain-security)
-   [NIST 800-171 3.2.1 Ensure that managers, systems administrators, and users of organizational systems are made aware of the security risks associated with their activities and of the applicable policies, standards, and procedures related to](https://support.icompaas.com/support/solutions/articles/62000229264-nist-800-171-3-2-1-ensure-that-managers-systems-administrators-and-users-of-organizational-systems-)
-   [CMMC 2.0 AT.2.056 Ensure that managers, systems administrators, and users of organizational systems are made aware of the security risks associated with their activities and of the applicable policies, standards, and procedures related to t](https://support.icompaas.com/support/solutions/articles/62000229422-cmmc-2-0-at-2-056-ensure-that-managers-systems-administrators-and-users-of-organizational-systems-a)

## 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.