Attackers are stealing your vendor’s source code

The first issue

A compromised developer account. That's all it took. The attackers traced it to an exposed GitLab instance and walked right in. For twelve months, they had access to the most sensitive information F5 possessed—the actual code that runs the infrastructure for most of the world's largest companies.

What F5 did

They disclosed the breach. They brought in investigators. They locked down the compromised systems. But the damage was already done. The source code was gone. The vulnerability research was gone. And attackers now had a blueprint for developing exploits.

Here's where it gets worse for everyone else

If you're using F5's load balancers or traffic management products, attackers now have the source code. They can analyze it for vulnerabilities F5 hasn't discovered yet. They can develop exploits specifically designed to bypass F5's security controls. They can target the exact systems your organization depends on.

You didn't get breached. Your vendor did. But you're still vulnerable.

This is a SolarWinds-level concern

When attackers steal source code from infrastructure vendors, they're not just compromising one company, they're gaining leverage over every organization that depends on that vendor's products.

The security teams at those 80% of Fortune 500 companies did everything right. They vetted F5. They configured their systems properly. They followed best practices. And they're still exposed—because their vendor's source code is now in the hands of state-sponsored attackers.

So how do you actually protect against this?

You can't prevent every vendor breach. But you can architect your security assuming vendors will be compromised. That means treating vendor source code exposure as a risk factor in your supply chain assessments. It means monitoring for unusual exploit activity against vendor products you depend on. It means having incident response procedures that account for vendor-wide vulnerabilities affecting multiple organizations simultaneously.

Most importantly, it means understanding software development security principles well enough to assess what vendor source code exposure actually means for your risk profile. Not every source code leak creates the same level of risk—it depends on what's in that code, how it's used in your environment, and what attack vectors it enables.

Organizations need security professionals who can make these architectural and risk management decisions. Who understand software development security well enough to evaluate vendor risks. Who can think strategically about supply chain dependencies when the threat landscape changes overnight.

If you'd like to learn these principles in depth, this is exactly what CISSP Domain 8 (Software Development Security) and Domain 1 (Supply Chain Risk Management) cover. Our CISSP bootcamp teaches you to think about security architecture and vendor risk at this level—before your critical infrastructure becomes someone else's exploit development playground.

Our next CISSP bootcamp starts January 12-16, 2026.

Stay secure,
The DestCert Team

P.S. Don't have 5 days but still interested in taking the CISSP? Explore our self-paced option.