Creating an Ephemeral Firefox Browser with Docker

In this guide, we'll create a disposable Firefox browser using Docker that automatically destroys its session after use. This is perfect for opening potentially risky links without leaving traces on your system.

Note: It is very useful because it allows changing the Firefox language, which helps avoid browser detection.

Step 1: Create the Dockerfile

First, let's create a Dockerfile that will set up our ephemeral Firefox environment:

root@kali:~/firefox-ephemeral# cat Dockerfile
FROM debian:bookworm

ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update && \
    apt-get install -y \
        firefox-esr \
        libgtk-3-0 \
        libdbus-glib-1-2 \
        libx11-xcb1 \
        libasound2 \
        x11-utils && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/*

ENTRYPOINT ["firefox-esr"]

Step 2: Build the Docker Image

Build the Docker image with the following command:

root@kali:~/firefox-ephemeral# docker build -t firefox-ephemeral .
Sending build context to Docker daemon  2.048kB
Step 1/3 : FROM debian:bookworm
 ---> 1234567890ab
Step 2/3 : ENV DEBIAN_FRONTEND=noninteractive
 ---> Running in abcdef123456
Step 3/3 : RUN apt-get update &&     apt-get install -y         firefox-esr         libgtk-3-0         libdbus-glib-1-2         libx11-xcb1         libasound2         x11-utils &&     apt-get clean &&     rm -rf /var/lib/apt/lists/*
 ---> Running in 7890abcdef12
Successfully built 1234567890ab
Successfully tagged firefox-ephemeral:latest

Step 3: Install XQuartz

Install XQuartz using Homebrew:

user@mac:~# brew install --cask xquartz
==> Downloading https://dl.bintray.com/xquartz/downloads/XQuartz-2.8.1.dmg
######################################################################## 100.0%
==> Installing Cask xquartz
==> Moving App 'XQuartz.app' to '/Applications/XQuartz.app'
==> Linking Binary 'xauth' to '/usr/local/bin/xauth'
==> Linking Binary 'xhost' to '/usr/local/bin/xhost'
==> Linking Binary 'xmodmap' to '/usr/local/bin/xmodmap'
==> Linking Binary 'xrdb' to '/usr/local/bin/xrdb'
==> Linking Binary 'xset' to '/usr/local/bin/xset'
==> Linking Binary 'xsetroot' to '/usr/local/bin/xsetroot'
==> Linking Binary 'xterm' to '/usr/local/bin/xterm'

Step 4: Configure X11

Run these commands in your terminal:

user@mac:~# export DISPLAY=:0
user@mac:~# /opt/X11/bin/xhost + 127.0.0.1
127.0.0.1 being added to access control list

Open X11 preferences and enable "Allow connections from network clients". IMPORTANT: After enabling network clients in X11, you must restart your machine for the changes to take effect.

X11 Configuration

Step 5: Test the Setup

Test if everything works by running:

/usr/local/bin/docker run -e DISPLAY=host.docker.internal:0 \
  -v /tmp/.X11-unix:/tmp/.X11-unix \
  --rm firefox-ephemeral "https://4rji.com"
Firefox Test

Step 6: Create an Automation Script

Firefox Test
  • Download

    • Step 7: Create a Shortcut

    Create a shortcut using Loudepeck or Apple Shortcuts to run the script. This will allow you to open any link in your clipboard in the ephemeral Firefox browser.

    Shortcut Setup
    Shortcut Setup

    Remote SSH Configuration

    We can also achieve the same using an SSH session. For example, on the remote server we create the same container and use the following script with our remote IP:

    #!/bin/bash
export DISPLAY=10.0.4.180:0
docker run -e DISPLAY=$DISPLAY \
  -v /tmp/.X11-unix:/tmp/.X11-unix \
  --rm \
  --name ff-ephemeral \
  firefox-ephemeral "$1"

    Then we simply call the script from our machine with the following command:

    ssh kali-thp -Y "/home/kali2/firefoxephemeral https://4rji.com"

    This opens Firefox remotely, which is useful for viewing links in remote sessions or with different IPs.

    Now you can safely open any link in your clipboard using the ephemeral Firefox browser. The browser will be destroyed after use, leaving no traces on your system.