Your security posture is only as strong as your weakest vendor. Third-party breaches — where attackers compromise a supplier to reach their actual target — are now one of the most significant threat vectors facing organizations. Here’s how to manage it.
Why Third-Party Risk Has Exploded
Modern organizations share data and system access with hundreds of vendors: cloud providers, SaaS applications, payroll processors, IT service providers, legal firms, marketing agencies. Each vendor with access to your systems or data is a potential entry point for attackers. High-profile supply chain attacks have demonstrated that even large, sophisticated organizations are vulnerable through their vendor relationships.
Building a Third-Party Risk Program
Step 1: Inventory your vendors. Most organizations don’t have a complete picture of who has access to their systems and data. Start with a vendor inventory that captures what each vendor accesses, what data they handle, and how they connect to your environment.
Step 2: Tier your vendors by risk. Not all vendors present equal risk. A vendor with admin access to your production environment is higher risk than a vendor who receives invoices by email. Tier vendors by the access they have and the sensitivity of the data they handle, and apply due diligence proportionate to that risk.
Step 3: Conduct security due diligence before onboarding. Require security questionnaires, SOC 2 reports, penetration test results, or security ratings before granting access. The depth of due diligence should match the vendor’s risk tier.
Step 4: Include security requirements in contracts. Security requirements should be contractual obligations: minimum security controls, breach notification timelines, right to audit, and data handling requirements. Contracts without these provisions leave you without recourse when a vendor has an incident.
Step 5: Monitor continuously. Vendor risk doesn’t end at onboarding. Monitor for security incidents at your vendors, review SOC 2 reports annually, and reassess high-risk vendors when significant changes occur.