Step by Step to Install Firejail on Ubuntu 20.04 LTS

Firejail is a free & open source linux security SUID tool. It is used for untrusted applications securely run on system. It can be used to minimize the security issues of system.

There are few steps to install firejail on ubuntu:

Step 1: Update the System.

apt-get update

Step 2: Install the Firejail on system.

apt-get install firejail

• Check the firejail version.

firejail --version

• Here is the command output.

Step 3: Firejail syntax & Examples.

firejail <application-name>

• To untrusted applications in a secured environment.

firejail firefox

• Here is the command output.

• To configure symlinks on system.

firecfg

• Here is the command output.

• To list all the sandboxed applications.

firejail --list

• To show all the processes.

firejail --top

• To shutdown the sandbox  by PID.

firejail --shutdown=PID
or
firejail --shutdown=4100

• To use firejail in private mode.

firejail --private <application>
or
firejail --private firefox

• Here is the command output.

Step 4: To Create Blacklisted Profiles.

• To create a directory.

mkdir -p .config/firejail/

• Change the directory path.

cd .config/firejail/

• To copy the default security profile into created directory.

cp /etc/firejail/default.profile app.profile

• Open the file.

vim app.profile

• If we want to black list Downloads directory.Edit the followiing line:

Blacklist /home/ubuntu/Downloades

• If we want to Documents directory as read only.Edit the following line:

Read-only /home/user/Documents

• Here is the command output.

• Now profile is Ready.To run the following command for untrusted application in limited environment.

firejail app.profile