How to remediate – WatchGuard FireboxV and XTM Fireware OS Web Detection

1. Introduction

The web UI for a WatchGuard FireboxV or XTM running Fireware OS has been detected on a remote host. This means an administrative interface is accessible, potentially allowing attackers to gain control of the firewall. Successful exploitation could lead to data breaches, service disruption, and loss of network security. This affects systems running WatchGuard FireboxV or XTM appliances with Fireware OS enabled. A likely impact is compromise of confidentiality, integrity, and availability.

2. Technical Explanation

The detection indicates the presence of a web-based management interface for WatchGuard firewalls. This interface allows administrators to configure and manage the device remotely. The plugin attempts to retrieve Fireware OS version information using HTTP Basic authentication if credentials are provided, indicating potential exposure. There is no known CVE currently associated with this specific detection; it flags an accessible administrative UI which may be running a vulnerable version of Fireware OS.

• Root cause: An accessible web management interface exists on the network.
• Exploit mechanism: An attacker could attempt to brute-force or use known credentials to access the web UI and then exploit any vulnerabilities present in the installed Fireware OS version.
• Scope: WatchGuard FireboxV and XTM appliances running Fireware OS.

3. Detection and Assessment

Confirming whether a system is vulnerable involves checking for the presence of the web UI and identifying the Fireware OS version. A quick check can determine if the interface is accessible, while more thorough methods reveal the specific version.

• Quick checks: Use a web browser to access the firewall’s default IP address (typically 192.168.1.1) and look for the WatchGuard login page.
• Scanning: Nessus plugin ID 30446ff8 can detect this vulnerability. This is an example only, other scanners may also provide similar detection capabilities.
• Logs and evidence: Check firewall logs for connections to port 80 or 443 from unexpected sources attempting access to the web UI.

ping 

4. Solution / Remediation Steps

Fixing this issue involves securing access to the web interface and ensuring the Fireware OS is up-to-date. These steps should be performed carefully to avoid service disruption.

4.1 Preparation

• No services need stopping for this remediation, but access restrictions are recommended during implementation.
• A roll back plan involves restoring the previous configuration from the backup. A change window may be needed to minimise disruption.

4.2 Implementation

1. Step 1: Change the default administrator password immediately if it has not already been done. Use a strong, unique password.
2. Step 2: Restrict access to the web UI by IP address using firewall rules. Allow only trusted management networks or hosts to connect.
3. Step 3: Update Fireware OS to the latest stable version available from WatchGuard’s website.

4.3 Config or Code Example

Before

# Default access allowed from any source (example)
access-list default permit ip any any

After

# Access restricted to trusted management network (example)
access-list management_ui permit ip 192.168.10.0/24 any

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this issue and similar vulnerabilities. These include least privilege access, strong password policies, and regular software updates.

• Practice 1: Least privilege – limit access to the web UI only to those administrators who require it.
• Practice 2: Strong passwords – enforce complex passwords for all administrative accounts.

4.5 Automation (Optional)

Automation is not directly applicable to this detection, but configuration management tools can be used to enforce access restrictions and update Fireware OS.

# Example Ansible task to restrict web UI access (example only - requires WatchGuard modules)
- name: Restrict Web UI Access
  watchguard.firewall.access_list:
    name: management_ui
    rule: permit ip 192.168.10.0/24 any

5. Verification / Validation

• Post-fix check: Attempt to access the web UI from an untrusted IP address; it should be blocked by firewall rules.
• Re-test: Re-run Nessus plugin ID 30446ff8; it should no longer report the vulnerability if the interface is inaccessible or running a patched version of Fireware OS.
• Smoke test: Verify that authorized administrators can still access and manage the firewall through the web UI.
• Monitoring: Monitor firewall logs for failed login attempts to the web UI from unexpected sources.

ping  -c 1 # Should not respond if blocked by ACL

6. Preventive Measures and Monitoring

Preventive measures include updating security baselines, incorporating checks into CI/CD pipelines, and establishing a regular patch management process.

• Baselines: Update your firewall baseline to require strong passwords and restricted access to the web UI.
• Asset and patch process: Implement a regular schedule for reviewing and applying security patches to all firewalls.

7. Risks, Side Effects, and Roll Back

Changing firewall rules can inadvertently block legitimate access if not configured correctly. Restoring the previous configuration is the primary roll back step.

8. References and Resources

• Vendor advisory or bulletin: https://www.watchguard.com/wgrd-products/firewall-appliances
• NVD or CVE entry: http://www.nessus.org/u?30446ff8