# System Security

System security is the first line of defense in a layered security strategy. It gives your phone system its baseline protection against known attacks and common breach techniques, and it is where hardening begins before you add network and account controls on top. Two practices carry most of the weight here: staying on current firmware and shutting off Secure Shell (SSH) access.

## Keep firmware up to date

Firmware is the low-level software that runs the phone system itself. Each firmware release closes bugs and patches vulnerabilities that have come to light since the previous build, so the newest version is almost always the most secure one available. Newer releases also add protection features that simply do not exist in older firmware. For both reasons, running current firmware is one of the most effective things you can do to keep the system safe.

The practical approach is to have Cloud Voice watch for new releases on a schedule and alert you, then apply the upgrade yourself when you are ready.

1. Go to **Maintenance > Upgrade**.
2. Under **Automatic Upgrade**, choose **Check for updates and notify me**, then set how often and at what time the system should look for new firmware.

   :::note
   This option only checks for releases and notifies you. It does not install anything on its own. You review the alert and run the upgrade manually, which keeps you in control of when the system goes down.
   :::

   ![Automatic upgrade settings with the check-and-notify option and a schedule selector](/images/pbx/automatic-upgrade-pce.png)
3. Click **Save**, then **Apply**.

Once a notification tells you a newer build is available, apply the upgrade manually when it suits you.

:::caution
Installing a firmware upgrade briefly takes the phone system offline and ends any calls in progress. Run the upgrade outside business hours so callers are not affected.
:::

## Turn off SSH access

Secure Shell (SSH) is a remote command-line login into the system. Attackers routinely scan the internet for exposed SSH servers and hammer them with brute-force attacks: thousands of username and password guesses per second until something works. A successful login hands them a foothold they can use for toll fraud (placing expensive calls, often international, at your expense) or to harvest sensitive data. Because of this, the safest posture is to leave SSH disabled and only switch it on when you genuinely need it for troubleshooting.

To disable it, go to **Security > Security Settings > Console/SSH Access** and switch **SSH Access** off.

:::note
This toggle controls only console and SSH command-line access. Turning it off does not affect the web management interface, so you will not lock yourself out of the admin portal.
:::

![The Console/SSH Access panel with the SSH Access toggle switched off](/images/pbx/security-disable-ssh-pce.png)

:::danger
If you enable SSH to troubleshoot, turn it back off as soon as you are finished. An SSH server left exposed is a standing toll-fraud risk, and it is easy to forget it is still on.
:::