Monitoring, review and change management of supplier services

What the control asks

On a regular basis the organization is to monitor, review and evaluate suppliers' security practices and service delivery and to manage changes to them. Purpose: keep information security and service delivery at the level set in the supplier agreements. Guidance: this oversight should confirm that the security terms are honoured, that incidents and problems are handled properly and that changes in the supplier's services or business situation do not disrupt delivery. A relationship management process should: check service performance against the agreement; track supplier-side changes such as service enhancements, new applications and systems, revised policies and procedures, and new or changed controls to fix incidents or improve security; track changes in the services themselves such as network changes, new technologies, new products, versions or releases, new development tools and environments, relocated facilities, and changed or added sub-suppliers or subcontracting; review supplier service reports and hold the progress meetings the agreement calls for; audit suppliers and sub-suppliers, alongside independent auditor reports where available, and follow up findings; exchange and review incident information as agreed; examine supplier audit trails and records of security events, operational problems, failures, fault tracing and disruptions; respond to and manage identified events or incidents; identify and manage vulnerabilities; review the security of the supplier's own supplier relationships; make sure the supplier keeps enough capacity and workable plans to hold agreed continuity levels after major failure or disaster (see 5.29 and 5.30, 5.35 and 5.36, and 8.14); make sure suppliers name people responsible for checking and enforcing compliance with the agreement; and regularly evaluate whether the supplier keeps adequate security. A designated person or team owns each relationship, with the technical skills and resources to check that requirements, especially security ones, are met, and deficiencies trigger appropriate action. ISO/IEC 27036-3 gives more detail.

Purpose in the standard’s terms, in our words: Keeps security and service delivery at the levels the supplier agreements set.

Attribute values in one line: Preventive; Confidentiality, Integrity, Availability; Identify; Supplier relationships security, Information security assurance; Governance and ecosystem, Protection, Defence.

The five attribute values

These are the published values for this control, from ISO/IEC 27002:2022 clause 4.2 and Annex A Table A.1. Where your own value differs, record the difference and the reason in the same row rather than replacing the published value.

Evidence an auditor asks for

The attribute is a claim about how the control behaves. The evidence is what proves it operates. Keep both, and keep them together.

• Service performance reports and minutes of periodic supplier review meetings
• Records of supplier changes (new technology, locations, releases, sub-suppliers) with the organization's assessment of each
• Supplier audit reports and reviews of independent auditor or attestation reports, with tracked follow-up of findings
• Incident and security event information received from suppliers and the organization's review of it
• Evidence of supplier continuity capability such as tested continuity plans or exercise results
• A named relationship owner for each critical supplier and records of actions taken on service deficiencies

Where audits commonly find gaps

• Supplier changes such as moving hosting location or adding sub-processors happen without notice or review
• Assurance reports are filed but exceptions in them are never followed up
• No one is accountable for monitoring security performance of a given supplier
• Supplier incident information is not integrated into the organization's incident process

What ISO/IEC 27028 changes for this control

It carries a single control type, preventive, which sets what the evidence has to prove. It contributes no detect function, so a control set built from this row alone would not show detection. It crosses 2 operational capabilities, so two teams share the work and the owner column matters. Its earlier numbering (15.2.1, 15.2.2) is kept in the register so an older audit file can still be traced. It serves more than one security domain, which is why a domain count taken by row understates the view.

The guidance expands how the five values are used; it does not change the control or add a requirement. A register that carries the values and the evidence can answer the attribute question for this control without a new document. A register that does not can add the columns at the next SoA version, with an owner and a review date.

Controls that share its values

• 5.19 Information security in supplier relationships
• 5.20 Addressing information security within supplier agreements
• 5.21 Managing information security in the ICT supply chain

Read the five attributes All 93 controls