Part 3: How Firmware Vulnerability Noise Masks Real Security Risks in Embedded Systems

firmware vulnerability noise

I remember the day I sat in front of a firmware image for a network appliance, two hundred megabytes of raw binary, stripped symbols, no debug info, and a report that quietly said: “3,412 CVE matches detected.”

My heart sank. Because I knew the worst thing we could do next was treat “3,412 matches” as meaningful intelligence.

What we were staring at was firmware vulnerability noise – loads of surface data, but no clear signal. And in the world of firmware, that kind of noise is a time-bomb.

Firmware Vulnerability Noise: When Static Scanning Becomes a False Comfort

When I entered embedded security, the industry loved the idea: run a scanner, list all known vulnerabilities (CVEs), boom – done. But here’s the truth I learned: many CVE hits in firmware are irrelevant, or even misleading.

Also Read: Part 2: Who Really Owns Firmware Security? Inside the Industry’s Blind Spot

A 2022 academic study of automated firmware CVE matching found that in tests with 127 router firmware images, naive version‐based matching incorrectly flagged an estimated 68% false positives.

In other words: more than two thirds of matches did not correspond to real exploitable conditions.
This means that the “noise” outweighs the “signal” more often than not.

Another large-scale firmware study collected over 759,000 files, filtered to 172,751 potential firmware images, then analyzed 32,356 of them.

Even there, one of the key challenges listed was filtering out the obvious noise (non-firmware files, irrelevant components). If we struggle to even identify what firmware is, how much harder is it to map meaningful vulnerabilities inside?

Firmware Vulnerability Noise: Why This Matters in the Real World

This isn’t just an academic quibble. It directly hits product teams, OEMs, suppliers and enterprises—especially those with long-lifecycle devices, large fleets, or supply-chain complexity.

  • OEMs and suppliers: If your scanner flags thousands of CVEs for your firmware image, you might assume you’re “covered.” But if 70% of those are false positives, you still don’t know what to fix. You waste resources chasing ghosts, and you may miss the real risk that slipped through.
  • Enterprises and operators: Suppose you’re deploying thousands of embedded devices (access points, IoT sensors, industrial gateways). You run firmware scanners, get reports, and assume you know your risk. You might not know which devices truly contain the vulnerable component — causing blind spots in your patch program.
  • Safety-critical domains: Devices in automotive, industrial control, or infrastructure can’t just be “patched tomorrow.” If your analysis pipeline is full of irrelevant alerts, the team can’t triage effectively – and that delay can translate into real risk.

Also Read: Part 1: The Invisible Perimeter – Why Firmware Visibility Is the Next Security Frontier

Firmware Vulnerability Noise: The Anatomy of Noise

Let me walk you through what I’ve seen in multiple engagements – the kinds of things that inflate CVE counts but don’t deliver meaningful insights.

Duplicated libraries across products

I once found three different firmware images across a family of routers that shipped with a copy of libc compiled in slightly different ways. My scanner flagged the same CVE twice for each copy. That turned three alerts into nine.

But when I dug deeper, the CVE didn’t apply to how the library was used in that context – architecture differences, altered build flags, missing vulnerable code paths made it moot.

Imagine doing that for hits that are more than just 100 manually? You will spend your whole budget for a quarter trying to triage what is real and what is noise!

Firmware Vulnerability Noise: Stripped Symbols and Unknown Build Information

Many firmware binaries are stripped of function names and compile metadata. Without those, matching versions is guesswork. One vendor told me: “We just scanned all binaries and treated any old version number as a hit.”

That approach generated thousands of hits – but only a handful turned out to be exploitable. Finding something of value in such scenarios requires a combination of reverse engineering knowledge, previous know-how, already available functions that are somehow closer to what you are trying to triage? Still with me? Imagine doing this for your whole line of product with 2 personnel research team.

Also Read: ECU Security: Inside the Reverse-Engineer’s Mind – How ECUs Are Hacked

Firmware Vulnerability Noise: Version-centric matching vs real code relevance

Version numbers can lie. Vendors will back-port patches or remove vulnerable code paths without incrementing version numbers.

The study I mentioned earlier showed that version‐based matching in firmware leads to enormous false positive rates. Without context – architecture, build flags, code path exposure – you’re essentially guessing.

Component Reuse Across Product Lines

One supplier reused the same SDK across three product lines. A single older component triggered multiple alerts across each product.

The scanner flagged each instance separately but didn’t help the team see that this was the same underlying issue. They were chasing three “instances” of a component they thought were independent.

Triage: The Missing Piece of the Puzzle

If the core of the problem is too many matches, the answer isn’t “run more tools.” It’s “run smarter triage.” Here’s what needs to be in place (and rarely is):

  • Architecture-Awareness: Are these binaries for ARM7, MIPS, x86, or something custom? Mismatch means the CVE may not apply.
  • Dependency Mapping: Which library used by which binary? Is that library actually exposed in the runtime?
  • Code Provenance: When was it built? What compiler? Which variant? Which functions are enabled?
  • Contextual Filtering: Is the component ever reachable from an attack surface? Does the binary expose the vulnerable code path, or was it effectively stubbed out?

In one case I worked on, the team had a list of 1,200 flagged CVEs for a set of gateways. After triaging that applied the above filters, the actionable list dropped to 17 items. Seventeen. That’s the difference between chaos and clarity.

Firmware Vulnerability Noise: Visibility ≠ Scanning

When I say “visibility,” this is what I mean: the ability to see and reason about what’s inside a device – not just “what versions” it contains.

Scanning tools give you versions and hits. Visibility gives you insight: “Component X on device Y, built in March 2023, with feature set Z, reachable by interface I.”

That insight is what separates a security team that is reactive from one that’s strategic.

I’ve witnessed vendors treat firmware analysis like a checkbox: run scanner → export CSV → move on. But in the moment when a real exploit chain triggers, those CSVs become useless. You might know you “have CVE ABC” – but you don’t know where, how, or why.

Firmware Vulnerability Noise: An Enterprise Facing a CVE Tsunami

Let me share a real-world scenario (anonymized, but typical).

An enterprise manages 5,000 IoT devices across multiple sites. One day, a high-profile CVE in an open-source stack used broadly in embedded systems is published. The scanners light up – hundreds of devices flagged.

They launch a triage effort. First pass: mark all flagged devices as “potentially vulnerable,” initiate firmware roll-out with vendor.

Weeks later, they still don’t know which devices truly require the update, so they treat all of them as exposed. That delays response, increases cost, and eats manpower.

Meanwhile, another team digs deeper: they find that only ~8% of the flagged devices actually contain the vulnerable code path (based on architecture and build metadata).

The rest were false alarms. If they’d known that immediately, their response plan would’ve been laser-focused, not scatter-gun.

Also Read: Why ECU Tuning Could Be the Weakest Link in Automotive Cybersecurity

Firmware Vulnerability Noise: Why the Timing is Critical

We’re in a moment where firmware complexity, supply-chain dependence, and regulatory pressures all push in the same direction. At the same time, the tools and processes for firmware visibility are immature. That mismatch is what creates the gap.

Firmware ecosystems are diverse: many architectures, many third-party modules, many reuse patterns.
Many devices have long lifetimes, meaning code built years ago still runs today.

Hardware constraints (custom chips, stripped binaries, unknown toolchains) make detection harder.
Teams are still using scanning-first mindsets, not visibility-first mindsets.

If you wait for perfect tools, you’ll be years behind. The smarter move is to build a visibility posture that recognizes the noise problem and deals with it.

Firmware Vulnerability Noise: The Take-Away

Don’t be fooled by big CVE count reports. Scores in the thousands may actually hide how little of that is actionable. Treat every firmware scan result as input, not output. The real work is in triage and context. Visibility is not scanning → it’s analyzing, understanding, and making decisions.

The organizations that adapt this mindset now will have the advantage when the next firmware-level exploit chain appears.

Because when everyone else is scrambling with CSV exports and false alarms, your team will already know which devices matter, which code matters, and what you need to act on.

Author

  • Ghost Collective

    Ghost Collective: We are a team focused on offensive security for production automotive electronics. For many years we’ve been reversing, compromising, and auditing real-world ECUs and in-vehicle devices (Infineon TriCore, Renesas RH850, NXP MPC5xxx and similar families). Our work blends black-box and white-box diagnostic exploitation, on-target debugging, firmware triage, persistent implant simulation, and threat-intelligence collection. We also audit commercial tuning toolchains to identify the exact techniques and vulnerabilities they use to access and modify production ECUs so OEMs and Tier-1s can harden their diagnostic surfaces and remediation workflows.

Back to top