SEA-23.1: Virtual Machine Images
Mechanisms exist to ensure the integrity of virtual machine images at all times.
Renumbered: Formerly CLD-05 in SCF 2025.4.
Control Question: Does the organization ensure the integrity of virtual machine images at all times?
EMEA (1)
| Framework | Mapping Values |
|---|---|
| EMEA Germany C5 2026 | OPS-26.03B OPS-34.01B.1 OPS-34.01B.2 PSS-11.01B PSS-11.01B.1 PSS-11.01B.3 PSS-11.01B.4 |
APAC (2)
| Framework | Mapping Values |
|---|---|
| APAC Malaysia RMiT 2025 | A10-B2(c)(ii) A10-B3(b) |
| APAC Singapore MAS TRM 2021 | 11.4.3 |
Capability Maturity Model
Level 0 — Not Performed
Practices are non-existent, based on the inability to demonstrate an implemented and operational capability. A reasonable person would conclude the control is not being performed.
Level 1 — Performed Informally
Cloud Security (CLD) domain capabilities are ad hoc and inconsistent. Capability criteria associated with this control may include: ▪ Policies, standards & procedures associated with CLD domain capabilities provide limited coverage due to the depth and breadth of the existing documentation. ▪ Cloud management-related activities are decentralized (e.g., a localized/regionalized function) and uses non-standardized methods to implement secure, resilient and compliant practices.
Level 2 — Planned & Tracked
Cloud Security (CLD) capabilities are requirements-driven, but are not standardized across the entity (e.g., local/regional level consistency). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with CLD domain capabilities are formally documented and centrally-managed by the entity. ▪ Standardized Operating Procedures (SOP) associated with CLD domain capabilities are documented and maintained by process owners. ▪ IT and/or cybersecurity personnel work with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with CLD domain capabilities to address applicable statutory, regulatory and/or contractual requirements for Technology Assets, Applications, Services and/or Data (TAASD). ▪ Cloud management controls-related controls are primarily administrative and preventative in nature (e.g., policies, standards and procedures & guidelines). ▪ Cloud management may be a defined function (e.g., team or department) or assigned as an additional duty to existing IT and/or cybersecurity personnel. ▪ Cloud-based Technology Assets, Applications and/or Services (TAAS) are governed according to the same processes used for on-premises TAAS, where no formal, dedicated cloud governance process exists.
Level 3 — Well Defined
Secure Engineering & Architecture (SEA) capabilities are standardized across the entity for applicability to People, Processes, Technologies, Data and/or Facilities (PPTDF) to ensure consistency for Technology Assets, Applications, Services and/or Data (TAASD). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with SEA domain capabilities are formally documented and centrally-managed by the entity's Governance, Risk & Compliance (GRC) team, or similar function. ▪ Standardized Operating Procedures (SOP) associated with SEA domain capabilities are well-documented and kept current by process owners. ▪ A cybersecurity engineering / architecture team, or similar function, is appropriately staffed and supported to implement and maintain RSK domain capabilities. ▪ Technology is leveraged to enhance the efficiency and accuracy of secure engineering management operations (e.g., project management solution). ▪ The entity's Governance, Risk & Compliance (GRC) team, or similar function, works with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with SEA domain capabilities to address Minimum Compliance Requirements (MCR) (e.g., applicable statutory, regulatory and/or contractual requirements) and Discretionary Security Requirements (DSR) (e.g., entity-required controls). ▪ Secure Baseline Configurations (SBC) enforce the secure engineering principles on all applicable Technology Assets, Applications and/or Services (TAAS). ▪ An implemented and operational capability exists to ensure the integrity of virtual machine images at all times.
Level 4 — Quantitatively Controlled
Compliance (CPL) capabilities, in addition to being standardized across the entity and centrally managed to ensure consistency across Technology Assets, Applications, Services and/or Data (TAASD), efforts are metrics driven to provide sufficient insight for decision makers to predict optimal performance, ensure continued operations and/or identify areas for improvement. Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Applicable SCR-CMM Level 3 (Well Defined) capabilities are implemented and operational. ▪ Metrics reporting includes quantitative analysis of Key Performance Indicators (KPIs). ▪ Metrics reporting includes quantitative analysis of Key Risk Indicators (KRIs). ▪ Scope of metrics, KPIs and KRIs covers organization-wide cybersecurity and data protection controls, including functions performed by third-parties. ▪ Organizational leadership maintains a formal process to objectively review and respond to metrics, KPIs and KRIs (e.g., monthly or quarterly review). ▪ Based on metrics analysis, process improvement recommendations are submitted for review and are handled in accordance with change control processes. ▪ Business and technical stakeholders are involved in reviewing and approving proposed changes to evolve capabilities.
Level 5 — Continuously Improving
Utilize SCR-CMM Level 3 or Level 4 (if available) criteria definitions: ▪ There are no defined Level 5 criteria, since it is reasonable to assume a continuously-improving process is not necessary to operationalize this control. ▪ Level 5 capabilities should be considered “world-class” where the control builds on Level 4 capabilities, but are continuously improving through Artificial Intelligence (AI) and/or Machine Learning (ML) technologies. ▪ While it may be possible to develop responsive capabilities for this control through the use of AI and/or ML technologies, the criteria would be organization-specific to define.
Assessment Objectives
- SEA-23.1_A01 the integrity of virtual machine images is protected at all times.
- SEA-23.1_A02 virtual machine images are governed according to the organization's established change control processes.
Technology Recommendations
Micro/Small
- Use cloud provider-supplied images; keep golden images updated
Small
- Golden VM images maintained and hashed
- Images stored with restricted access
Medium
- Image pipeline with integrity verification (e.g., HashiCorp Packer, Azure Image Builder)
- Image repository access control
- Regular image rebuilds
Large
- Golden image pipeline with signing and vulnerability scanning
- Image integrity monitoring (e.g., CimTrak, Tripwire)
- Immutable image repositories
Enterprise
- Enterprise image management with signed, scanned and versioned images (e.g., EC2 Image Builder, Azure Compute Gallery, Packer)
- Continuous integrity verification and drift detection
- Policy enforcement against unapproved images