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Vendor Security Assessments and Third-Party Risk Reviews

How to Conduct Vendor Security Assessments and Third-Party Risk Reviews

In today’s interconnected digital world, third-party vendors play a vital role in operations—but they can also introduce risk. A strong vendor security assessment process ensures that external partners meet your organisation’s security requirements and regulatory obligations.

Below is a structured approach to evaluating third-party risk and conducting periodic security audits.


🔍 1. Define Your Assessment Criteria

Before engaging with vendors, clearly outline what you’re assessing. This includes:

  • Data sensitivity: What type of data will the vendor access or process?
  • Regulatory requirements: e.g. GDPR, HIPAA, PCI-DSS.
  • Business impact: Would a compromise affect your operations or reputation?

Create a vendor classification system:

  • Tier 1: High-risk vendors (access to sensitive data or systems).
  • Tier 2: Medium-risk (limited access, non-critical services).
  • Tier 3: Low-risk (no data or system access, e.g. office supplies).

📄 2. Distribute Security Questionnaires

Send a tailored security questionnaire (or use a framework like CAIQ or SIG) that covers:

  • Access controls and user management
  • Data encryption (at rest and in transit)
  • Incident response capability
  • Vulnerability management
  • Business continuity and disaster recovery
  • Compliance with standards (ISO 27001, SOC 2, etc.)

Tools such as OneTrust, Prevalent, or Whistic can streamline this process.


🔐 3. Review Evidence and Validate Claims

Don’t just take answers at face value. Ask for:

  • Security policy documentation
  • Third-party audit reports (SOC 2 Type II, ISO 27001, etc.)
  • Penetration test summaries
  • Data flow diagrams

Validate that controls align with your risk tolerance. Look for gaps or red flags, such as unencrypted backups or poor access control.


🔁 4. Perform Periodic Security Audits

For high-risk vendors, schedule annual or semi-annual audits. These can include:

  • Onsite assessments (if possible)
  • Vulnerability scans
  • Review of logs or access records
  • Interviews with vendor security personnel

Document findings and track remediation progress through a risk register or GRC platform.


🛡 5. Manage and Track Risk

Assign a risk rating to each vendor (e.g. low, medium, high) and maintain a Vendor Risk Register. Actions include:

  • Requiring remediation plans
  • Applying compensating controls
  • Terminating the relationship if risk is unacceptable

Use tools like ServiceNow VRM, Archer, or even Excel + SharePoint for tracking if budget is limited.


📆 6. Reassess on Contract Renewal or Major Changes

Re-evaluate security posture when:

  • A contract is renewed
  • The vendor experiences a breach
  • Services or scope of data changes

Always include security terms in your contracts, such as breach notification timelines, right to audit, and data handling clauses.


✅ Summary

Vendor security assessments help reduce your organisation’s exposure to third-party risk. A mature process should include:

  • Clear risk classification
  • Structured questionnaires
  • Evidence review
  • Periodic audits
  • Ongoing risk tracking and governance

Implementing this process ensures compliance, builds trust, and enhances your overall cybersecurity posture.

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