Finite State Blog

Black Box to Clarity: Breaking Open Firmware Security

Written by Robert Kelley | Sep 22, 2025 10:38:45 PM

Firmware is often treated as a black box. Manufacturers know what the device is supposed to do, but what’s really inside the firmware can feel opaque, even to the people who built it.

Attackers don’t see it that way. They treat every firmware image as a puzzle to solve. And as a penetration tester, I do the same.

 

The Challenge of the Black Box

When I’m handed a device with no documentation, no source code, and no version information, I treat it like an attacker would. The first challenge is simply extracting the firmware, pulling data from a flash chip, identifying a UART interface, or using tools to carve a binary image off the device.

Once I have the firmware, the real work begins: unpacking, disassembling, and mapping the trust model. This is where the most critical issues often emerge:

  • Outdated SSL/TLS libraries with known CVEs.

  • Unsigned or weakly signed update mechanisms.

  • Hard-coded credentials or private keys.

  • Backdoors left behind from development or manufacturing.

Any one of these can compromise the security of an otherwise well-designed product.

 

From Manual Testing to Scalable Intelligence

Manual reverse engineering is powerful, but it’s also time-consuming. Fully unpacking and analyzing a complex firmware image can take days or weeks, which makes the process incredibly hard to scale. That’s where Finite State makes the biggest difference for pen-testers.

Our platform automates many of the most tedious parts of the process, including:

  • Firmware unpacking and binary analysis to reveal hidden components.

  • SBOM generation and enrichment to identify third-party dependencies and vulnerabilities.

  • Continuous monitoring against 200+ threat intelligence feeds to catch newly discovered CVEs.

This level of automation means I can quickly move past the mechanical work, gain actionable findings in a matter of hours, and focus my testing on the high-impact areas, chaining vulnerabilities together, simulating real attack paths, and validating the overall security model of a product.

 

Why This Matters

Without visibility into firmware, manufacturers are blind to some of their most critical risks. Attackers know how to pull apart binaries and exploit what they find, so the only way to stay ahead is to use the same techniques but at scale, with automation that keeps pace with evolving software supply chains.

Finite State bridges that gap. The platform provides the speed and breadth, and expert testing adds the depth and creativity. Together, that combination turns the black box into a clear picture of risk, one that manufacturers can act on before attackers do.

 

Learn More

Book a demo to see how Finite State transforms firmware analysis into actionable intelligence.