Set Up SFTP with Chroot on Ubuntu 24.04

Create restricted group

Creating a restricted group is the first step to setting up SFTP chroot on Ubuntu 24.04, which helps keep your users’ access limited to only what they need.

Run the command below to create a new group.

sudo groupadd chgroup

Next, run the command below and put a user in the chgroup created above.

sudo usermod -aG chgroup username

Replace username in the command above with the account’s actual username.

Configure SSH

Next, you’ll need to configure SSH to enable SFTP chroot on Ubuntu 24.04 by editing the main SSH settings file.

sudo nano /etc/ssh/sshd_config

Adjust the highlighted settings in the file.

# override default of no subsystems
# comment out the line below
#Subsystem      sftp    /usr/lib/openssh/sftp-server
Subsystem sftp internal-sftp

# add the lines below
Match Group chgroup
    X11Forwarding no
    AllowTcpForwarding no
    ChrootDirectory /home
    ForceCommand internal-sftp

Save the file and then exit.

Restart SSH by running the command below.

sudo  systemctl restart ssh

Test SSH and sFTP

After making the changes, it’s important to test your SFTP chroot setup on Ubuntu 24.04 to make sure it’s working correctly.

ssh richard@srv1.example.com's password:
This service allows sftp connections only.
Connection to srv1.example.com closed.

SFTP will succeed.

sftp richard@srv1.example.com's password:
Connected to srv1.example.com.
sftp>

You’re all set!

Conclusion:

Setting up a chroot restricted SFTP account on Ubuntu 24.04 enhances security by isolating user access to specific directories. Here are the key takeaways:

• Enhanced Security: Users are confined to their directory, minimizing the risk of unauthorized access to other users’ files.
• Group Management: Creating a specific group for SFTP users simplifies the management of user permissions and access.
• SSH Configuration: Proper configuration in the SSH settings is crucial for implementing chroot restrictions effectively.
• Testing: Always test your configuration to ensure that SFTP works as intended without compromising security measures.

Follow these steps to create a secure file transfer environment that’s still accessible for users.