Your cybersecurity strategy might be solid. You’ve invested in firewalls, endpoint protection, multi-factor authentication, and user training. But if you’re like most organizations, there’s still a major vulnerability lurking in your system, which isn’t even in your system. It’s your vendor.
This article explores the most overlooked risk in supply chain cybersecurity, why it’s so dangerous, and what mid-sized businesses and government contractors can do about it.
Your Network Is Bigger Than You Think
Every organization depends on third parties. Vendors, suppliers, subcontractors, managed service providers, SaaS platforms, and cloud providers. These partners often have access to your data, infrastructure, or systems.
And in most cases, they weren’t vetted to the same level your internal assets were.
Attackers know this. That’s why supply chain attacks are one of the fastest-growing and most effective cyber tactics today.
The #1 Risk: Assumed Trust
Most organizations treat vendor access as a checkbox. Once the relationship is active, it’s assumed to be safe. However, every connection, API, shared credential, or document exchange with a third party introduces a new risk.
The real threat isn’t just one specific vendor getting breached. It’s the cumulative exposure of your entire digital ecosystem.
Real-World Examples
- SolarWinds (2020): Attackers compromised a software update used by over 18,000 organizations, including federal agencies. The breach came through a trusted vendor’s system, not the targets’ own.
- Target (2013): Hackers accessed Target’s network through a third-party HVAC vendor, eventually stealing payment information for over 40 million customers.
Each case had one thing in common: the breach came through the supply chain.
Why This Risk Is Hard to See
- Lack of visibility. Many companies don’t even have a complete list of vendors with access to their network or data.
- Limited control. You can enforce policies on your employees but can’t directly control your vendors’ internal security practices.
- No ongoing monitoring. Initial due diligence might happen during onboarding, but few organizations re-assess vendors regularly.
- Complex subcontracting chains. One vendor might subcontract parts of their work to another, and you may not even know who’s touching your data downstream.
How to Reduce Supply Chain Cyber Risk
Here are practical steps you can take to protect your organization:
1. Map Your Vendor Ecosystem
Identify all third parties accessing your network, systems, or sensitive data. Don’t stop at Tier 1 vendors. Go deeper into subcontractors and SaaS integrations.
2. Classify Vendors by Risk
Not all vendors are equal. Group them based on access level, data sensitivity, and business impact if compromised.
3. Conduct Security Assessments
Send vendor questionnaires. Review their policies. Request evidence of compliance with standards like NIST 800-171, ISO 27001, or SOC 2. High-risk vendors should face deeper due diligence.
4. Add Security Clauses to Contracts
Make cybersecurity requirements part of your vendor agreements, including breach notification, minimum security standards, and audit rights.
5. Set Up Ongoing Monitoring
Don’t rely on one-time assessments. Use tools or managed services that help you track vendor risk continuously, especially for those with persistent access.
6. Create an Offboarding Process
Every vendor should have a clear offboarding checklist to remove system access, revoke credentials, and document data destruction when the engagement ends.
Compliance Matters Here Too
If you’re working with the Department of Defense, your supply chain isn’t just a business risk. It’s a compliance issue.
- CMMC Level 2 requires contractors to verify that any vendors handling CUI also meet the necessary controls.
- DFARS 252.204-7012 mandates that contractors submit cybersecurity requirements to all relevant subcontractors.
- NIST SP 800-171 control 3.1.20 calls for managing communications at system boundaries, especially with external entities.
Failing to account for your vendors could jeopardize your entire compliance standing.
Final Thought
Most cyber risks don’t come through the front door. It slips in through the back. Quietly, through trusted partners who didn’t know they were the weakest link. The most significant risk in your supply chain is assuming your vendors are as secure as you are.
At Black Rock Engineering & Technology, we help organizations map their vendor ecosystem, assess third-party risk, and build policies protecting the supply chain. Not just what’s in-house.
Need help building a more secure supply chain?
Take the first step toward closing the gap.