# BSI C5:2020 PSS-11 — Images for Virtual Machines and Containers - Source: https://support.icompaas.com/compliance/bsi-c5-2020/pss-11-images-for-virtual-machines-and-containers - Section: [Compliance](https://support.icompaas.com/compliance) › [BSI C5:2020 (Cloud Computing Compliance Criteria)](https://support.icompaas.com/compliance/bsi-c5-2020) › Platform & Service Security (PSS) - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **BSI C5:2020**·Criterion `PSS-11`·high·Component: **Platform & Service Security** ## What this control requires > Allows customers to restrict VM/container image selection and provides hardened CSP images with change notifications. Ensures secure configurations, protecting cloud customer data from vulnerabilities in virtualized environments. > > — BSI C5:2020, Criterion PSS-11 ### In plain English Allows customers to restrict VM/container image selection and provides hardened CSP images with change notifications. In practice, this means you can prove you security - configuration-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 **Platform & Service Security**, the assessor will trace your implementation back to the catalogue reference (Criterion PSS-11) 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. #### Configuration Management **Policy-as-code.** Codify the control as Service Control Policies (AWS), Azure Policy initiatives, or Organisation Policy (GCP) so the platform enforces what the document promises. **IaC.** Gate Terraform / Pulumi / CloudFormation changes with Checkov / tfsec / OPA so misconfigurations never reach production. **Drift.** Run a CSPM (Wiz / Prisma / Defender for Cloud / Security Command Center) over every account and route findings to a single risk register. #### Network Security **AWS.** VPC Flow Logs to S3, default-deny security groups, AWS Network Firewall for north-south, and Transit Gateway for hub-and-spoke segmentation. **Azure.** NSGs with deny-by-default, Azure Firewall Premium with TLS inspection, Private Endpoints for PaaS, and Microsoft Defender for Cloud's secure score for drift. **GCP.** VPC Service Controls perimeters around sensitive APIs, Cloud NGFW Enterprise for L7 inspection, Private Service Connect for managed services. ### Operational checklist - **Security.** Document the trigger, the owner and the cadence. - **Data.** Document the trigger, the owner and the cadence. - **Secure.** Document the trigger, the owner and the cadence. - **Images.** Document the trigger, the owner and the cadence. - **Scope:** - configuration, cloud customer data, environments, management. ## Evidence to collect - **Infra Scan.** Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings. Infrastructure posture tooling (AWS Config, Azure Policy, Nessus) verifies platform hardening. Focus: Images for Virtual Machines and Containers. ## 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. - Manual cloud-console changes that never make it back to Terraform — drift accumulates until the next outage forces a reconciliation. - Default-allow egress rules; East-West traffic with no segmentation; jump hosts on the public internet with password auth. ## 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. - [**NIST SP 800-171 Rev. 3 3.13.6** — Network Communications - Deny by Default - Allow by Exception](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-13-6-network-communications-deny-by-default-allow-by-exception) - [**NIST SP 800-53 Rev. 5 CM-2** — Baseline Configuration](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/cm-2-baseline-configuration) - [**ISO/IEC 27001:2022 A.5.34** — Privacy and protection of personal identifiable information (PII)](https://support.icompaas.com/compliance/iso-27001-2022/a-5-34-privacy-and-protection-of-personal-identifiable-information-pii) - [**CIS Controls v8 14.8** — Train Workforce on the Dangers of Connecting to and Transmitting Enterprise Data Over Insecure Networks](https://support.icompaas.com/compliance/cis-controls-v8/14-8-train-workforce-on-the-dangers-of-connecting-to-and-transmitting-enterprise-data) - [**GDPR Article 25** — Data protection by design and by default](https://support.icompaas.com/compliance/gdpr/article-25-data-protection-by-design-and-by-default) ## Related controls in BSI C5:2020 - [**Criterion PSS-10** — Software Defined Networking](https://support.icompaas.com/compliance/bsi-c5-2020/pss-10-software-defined-networking) - [**Criterion OPS-24** — Separation of Datasets in the Cloud Infrastructure](https://support.icompaas.com/compliance/bsi-c5-2020/ops-24-separation-of-datasets-in-the-cloud-infrastructure) - [**Criterion COS-06** — Segregation of data traffic in jointly used network environments](https://support.icompaas.com/compliance/bsi-c5-2020/cos-06-segregation-of-data-traffic-in-jointly-used-network-environments) - [**Criterion COS-04** — Cross-network access](https://support.icompaas.com/compliance/bsi-c5-2020/cos-04-cross-network-access) - [**Criterion INQ-01** — Legal Assessment of Investigative Inquiries](https://support.icompaas.com/compliance/bsi-c5-2020/inq-01-legal-assessment-of-investigative-inquiries) - [**Criterion PI-03** — Secure deletion of data](https://support.icompaas.com/compliance/bsi-c5-2020/pi-03-secure-deletion-of-data) ## 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 PSS-11` Topics: cloud infrastructurecloud postureconfiguration managementnetwork securitychange management ## 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.