seemoo-lab/nexmon

Free

The C-based Firmware Patching Framework for Broadcom/Cypress WiFi Chips that enables Monitor Mode, Frame Injection and much more

FreeFree tier

Type

Open Source

Company

seemoo-lab

Visit Website GitHub (38 stars)

About seemoo-lab/nexmon

Nexmon is a C-based firmware patching framework for Broadcom/Cypress WiFi chips, enabling users to write custom firmware patches to unlock capabilities such as monitor mode with radiotap headers, frame injection, and more. It supports a wide range of chips and operating systems, including Android, iOS, and Linux (Raspberry Pi). The project also provides auxiliary tools for advanced wireless research, including Wi-Fi jamming (using the chip as a software-defined radio), Channel State Information (CSI) extraction, ARM microcontroller debugging without JTAG, covert channels in Wi-Fi signals, and full software-defined radio capabilities. Note: Using nexmon may damage hardware and void warranties; users assume all risk.

Key Features

C-based firmware patching framework for Broadcom/Cypress WiFi chips

Enables monitor mode with radiotap headers

Enables frame injection

Supports a broad range of chips (bcm4330, bcm4335, bcm43455, etc.) and devices (Samsung Galaxy, Nexus 5, Raspberry Pi, iPhone 6, etc.)

Extensible to advanced features: Wi-Fi jammer, CSI extraction, ARM debugger, covert channels, SDR

Provides utilities like nexutil for interaction

Open source under permissive license

Pros & Cons

Pros

Open source and free
Comprehensive chip and device support
Active development with many related projects
Enables low-level Wi-Fi experimentation not possible with stock firmware
Well-documented with setup scripts and build tools

Cons

May damage hardware and void warranty
Requires technical expertise to compile and patch firmware
Not all chips/OS combinations are supported
Use at own risk; no official support

Best For

Wi-Fi monitoring and packet analysis with monitor modePenetration testing and network injectionChannel State Information (CSI) extraction for sensing and localizationWireless security research (jamming, covert channels)Using Wi-Fi chips as software-defined radiosDebugging ARM microcontrollers without JTAG

FAQ

What is nexmon?

Nexmon is a C-based firmware patching framework for Broadcom/Cypress WiFi chips that allows you to write custom patches to enable features like monitor mode, frame injection, and more.

Which chips and devices are supported?

Supported chips include bcm4330, bcm4335, bcm4339, bcm43430a1, bcm43455, bcm4345, and many others, running on devices such as Samsung Galaxy phones, Nexus 5, Raspberry Pi, iPhone 6, and more. See the DEVICES.md in the repository for the full list.

Is there a risk of damaging hardware?

Yes. The software may damage your hardware and void your warranty. You use it at your own risk and responsibility.

What advanced features are built on nexmon?

Related projects include a Wi-Fi jammer, a Channel State Information (CSI) extractor, an ARM debugger, a covert channel over Wi-Fi, and a software-defined radio (SDR) implementation using the Wi-Fi chip.