In this folder, you create a script that starts the emulation. In your Arm environment, you should now have a folder with the squashfs-root of the firmware you extracted.
#Arm emulator install#
You can install Terminator with: $ sudo apt-get install terminator You can SSH into the Arm environment with the shortcut “ssh arm”. Terminator is neat because it let’s you split screens more easily. $ rsync -av squashfs-root this terminal and open Terminator (red terminal icon in the side bar). From the folder binwalk extracted, run the following command to transfer the squashfs-root to the Arm environment. The emulation will make constant noise by spitting errors saying it can’t access certain peripherals. This is the terminal you can start your firmware emulation in. Inside the Azeria Labs VM, boot up the ARMv7 environment by clicking on the blue ARM icon in the sidebar. What you want from this is the Squashfs filesystem. $ wget $ unrar e $ binwalk -e US_AC6V1.0BR_V15.03.05.16_multi_TD01.binĦ4 0x40 TRX firmware header, little endian, image size: 6778880 bytes, CRC32: 0x80AD82D6, flags: 0x0, version: 1, header size: 28 bytes, loader offset: 0x1C, linux kernel offset: 0x1A488C, rootfs offset: 0x0ĩ2 0x5C LZMA compressed data, properties: 0x5D, dictionary size: 65536 bytes, uncompressed size: 4177792 bytesġ722572 0x1A48CC Squashfs filesystem, little endian, version 4.0, compression:xz, size: 5052332 bytes, 848 inodes, blocksize: 131072 bytes, created: $ cd _US_AC6V1.0BR_V15.03.05.16_multi_ Once you chose and downloaded your firmware, you need to unpack and extract the binary with binwalk. Many vendors let you download firmware versions from their website. Let’s say you want to emulate the Tenda AC6. Two small Arm exploitation challenges to learn the basics of bypassing XN (more details in the next blog post).All scripts necessary to start the firmware emulation.Two different Tenda router firmware versions (AC6 and AC15).QEMU emulated Armv7 environment ready to start.Don’t have a spare Arm processor? No problem, QEMU is your friend!įor those of you who want to save time and get straight into it, I have prepared a new Lab VM that contains:
#Arm emulator how to#
In this post, I will show you how to emulate Arm router firmware. But what if you don’t have the device? You download the firmware and emulate it. In that case you would gain root on the device via hardware hacking and drop gdbserver on the device and debug services remotely. You could also debug IoT firmware without emulating it. If you want to do security research on router firmware, for example, emulation can help you debug certain services and look for vulnerabilities. There are various reasons you might want to emulate firmware.