In the rapidly expanding Internet of Things (IoT) landscape, the security of embedded devices has become a critical concern. Billions of interconnected devices — from routers and cameras to smart home appliances and industrial sensors — often run on firmware that may contain vulnerabilities, hardcoded credentials, or misconfigurations. Identifying these weaknesses before malicious actors do is paramount. Enter Firmalyzer, an open-source, automated framework designed to streamline and deepen the process of IoT firmware security analysis.

What is Firmalyzer?

Firmalyzer is a Python-based tool created by Ismail Tasdelen. Its primary goal is to automate the tedious and complex tasks involved in dissecting IoT firmware images. Instead of manually extracting filesystems, hunting for binaries, and checking for common flaws, Firmalyzer provides a structured pipeline to perform these operations systematically.

The tool shines in its ability to:

  • Automatically extract firmware files from various container formats.
  • Identify the filesystem and unpack it to access the underlying binaries and configuration files.
  • Perform static analysis on key components to uncover potential security issues.

Key Features & Capabilities

  1. Automatic Extraction: Handles common firmware formats (.bin, .img, .trx, .chk, etc.) and compressed archives (.zip, .tar.gz, .7z). It uses tools like binwalk, jefferson, and ubireader under the hood.
  2. Filesystem Discovery & Unpacking: Probes the firmware to detect embedded filesystems (SquashFS, CramFS, JFFS2, YAFFS2, etc.) and extracts their contents for analysis.
  3. Targeted Static Analysis:
  • Web Application Analysis: Searches for web server root directories and scans for common vulnerabilities in web files (e.g., SQL injection, command injection, hardcoded credentials in scripts).
  • Binary Analysis: Identifies critical binaries (like /bin/httpd, /bin/ssh) and runs checks for non-PIE (Position Independent Executable) and stripped debugging symbols.
  • Dependency Checking: Uses readelf to list shared library dependencies, which can reveal outdated and vulnerable components.

4. Credential Mining: Actively searches for hardcoded passwords, API keys, and default credentials within configuration files, scripts, and binaries using pattern matching and dictionaries.

5. Emulation Potential: While focused on static analysis, the extracted filesystem provides a perfect base for dynamic analysis via emulation tools like QEMU.

6. Reporting: Generates structured findings, making it easier to document and prioritize issues.

Installation & Setup

Getting started with Firmalyzer is straightforward:

# 1. Clone the repository
git clone https://github.com/ismailtsdln/firmalyzer.git
cd firmalyzer

# 2. Install system dependencies (Ubuntu/Debian example)
# Firmalyzer relies on several external tools for extraction.
sudo apt-get update
sudo apt-get install binwalk python3-pip squashfs-tools unzip unrar p7zip-full -y

# 3. Install Python dependencies
pip3 install -r requirements.txt

Usage Guide: Step-by-Step

Let's walk through a typical analysis session.

Basic Analysis: The simplest way to run Firmalyzer is to provide a firmware image.

python3 firmalyzer.py -f /path/to/your/firmware.bin

This command will automatically trigger the extraction, unpacking, and default analysis modules.

Advanced Usage with Modules: Firmalyzer is modular. You can specify which analysis components to run.

# Extract only
python3 firmalyzer.py -f firmware.bin -m extractor

# Run specific analyzers (e.g., for web and binaries)
python3 firmalyzer.py -f firmware.bin -m web_analyzer,binary_analyzer

# Run the full suite of analyzers
python3 firmalyzer.py -f firmware.bin -m all

Targeting the Extracted Filesystem: If you've already extracted a filesystem (or are analyzing a live device's rootfs), you can point Firmalyzer directly at it.

python3 firmalyzer.py -d /path/to/extracted/rootfs/ -m all

Output: Firmalyzer prints its findings to the console, categorizing them by severity (High, Medium, Low, Info). It also saves the extracted firmware contents and a detailed log file in an output directory (default: ./output/).

Practical Use Case Example

Imagine you have a firmware file for a popular home router, WNR2000v5.bin.

Initial Reconnaissance:

python3 firmalyzer.py -f WNR2000v5.bin -m extractor

This unpacks the firmware. Inside the output folder, you find the SquashFS filesystem extracted to a directory like squashfs-root/.

Deep Dive Analysis:

python3 firmalyzer.py -d ./output/WNR2000v5/squashfs-root/ -m all
  • The web analyzer might find the www folder and flag a service.cgi script that unsafely passes user input to a system command.
  • The binary analyzer could identify that the /usr/sbin/lighttpd web server binary is not compiled as PIE, making Return-Oriented Programming (ROP) attacks easier.
  • The credential miner may discover a plaintext file with default admin credentials in /etc/passwd.

Result: Within minutes, you have a list of specific, actionable security findings that would have taken hours to uncover manually.

Firmalyzer in the Security Workflow

Firmalyzer is not a magical "vulnerability finder." It is a force multiplier for security researchers, penetration testers, and product security teams.

  • Researchers: Use it for large-scale analysis of multiple firmware images to find trends and 0-day vulnerabilities.
  • Pentesters: Quickly profile an IoT device during an engagement to identify low-hanging fruit and attack surface.
  • Vendor Teams: Integrate into CI/CD pipelines to catch common security misconfigurations before firmware ships.

Limitations & The Human Element

It's important to understand Firmalyzer's scope:

  • Static Analysis Only: It finds potential issues. False positives are possible (e.g., a hardcoded string that looks like a password but isn't). All findings must be validated manually.
  • Not a Dynamic Tool: It does not emulate or run the firmware to find runtime vulnerabilities like memory corruption.
  • Environment Dependent: Success in extraction depends on the underlying tools (binwalk, etc.) supporting the firmware's specific packing methods.

Firmalyzer successfully tackles the initial, most labor-intensive phase of IoT security assessment. By automating firmware unpacking and performing intelligent static analysis, it allows security professionals to focus their expertise on validating critical issues and developing exploits or mitigations.

For anyone involved in IoT security — from hobbyists to professionals — adding Firmalyzer to your toolkit is a smart move. It accelerates the reconnaissance process, ensures a more systematic approach, and helps uncover the hidden weaknesses within the devices that power our connected world.

Get started today:

GitHub Repository: https://github.com/ismailtsdln/firmalyzer

  • Explore the code, contribute, and report issues to help improve this valuable tool.

Disclaimer: Only use Firmalyzer on firmware you are authorized to analyze. Respect copyright and applicable laws.