How to remediate – Ansible Tower WebUI Detection

1. Introduction

Ansible Tower is an IT automation application running on a remote host. It allows users to orchestrate and manage infrastructure tasks. A publicly accessible web interface presents a potential attack surface. Successful exploitation could allow unauthorized access to the system, potentially leading to data breaches or service disruption. Confidentiality, integrity, and availability may be impacted.

2. Technical Explanation

The Ansible Tower WebUI is exposed, meaning it can be accessed from outside the local network. This allows attackers to attempt to exploit vulnerabilities in the web application itself. An attacker could potentially gain access to sensitive information or execute arbitrary commands on the server. There are no known CVEs associated with this specific detection; however, any unpatched vulnerability within Ansible Tower’s web interface is a risk. For example, an attacker might use cross-site scripting (XSS) to steal credentials from administrators accessing the UI.

• Root cause: The Ansible Tower WebUI is accessible remotely without sufficient security controls.
• Exploit mechanism: An attacker could attempt to exploit vulnerabilities in the web application, such as XSS or SQL injection.
• Scope: Affected platforms are those running Ansible Tower with a publicly accessible web interface.

3. Detection and Assessment

You can confirm whether Ansible Tower is exposed by checking network connectivity and the application’s version. A thorough assessment involves reviewing the application’s configuration for security best practices.

• Quick checks: Use curl -I https://<tower_ip_address>/ to check if the web interface is accessible.
• Scanning: Nessus plugin ID 139827 can detect Ansible Tower installations. This is an example only, and results should be verified.
• Logs and evidence: Check web server logs (e.g., Apache or Nginx access logs) for requests to the Ansible Tower URL.

curl -I https://<tower_ip_address>/

4. Solution / Remediation Steps

The following steps outline how to secure your Ansible Tower installation. These steps focus on limiting access and ensuring the application is up-to-date.

4.1 Preparation

• Ensure you have valid credentials for accessing the server and the Ansible Tower web interface. A roll back plan is to restore from the snapshot.
• Change window approval may be required by your organization’s security policy.

4.2 Implementation

1. Step 1: Restrict access to the Ansible Tower WebUI using a firewall or network ACL. Allow only trusted IP addresses or networks.
2. Step 2: Implement strong authentication measures, such as multi-factor authentication (MFA).
3. Step 3: Regularly update Ansible Tower to the latest version to patch known vulnerabilities.

4.3 Config or Code Example

Before

# Firewall rule allowing access from any source
iptables -A INPUT -p tcp --dport 8000 -j ACCEPT

After

# Firewall rule allowing access only from trusted IP address
iptables -A INPUT -s <trusted_ip_address> -p tcp --dport 8000 -j ACCEPT
iptables -A INPUT -p tcp --dport 8000 -j DROP

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this issue. Least privilege limits the impact of a successful attack, while input validation prevents malicious data from being processed.

• Practice 1: Implement least privilege by granting users only the necessary permissions.

4.5 Automation (Optional)

# Example Ansible playbook to restrict access via firewall
- name: Restrict access to Ansible Tower WebUI
  iptables:
    chain: INPUT
    protocol: tcp
    dport: 8000
    source: <trusted_ip_address>
    jump: ACCEPT
- name: Drop all other traffic to Ansible Tower WebUI
  iptables:
    chain: INPUT
    protocol: tcp
    dport: 8000
    jump: DROP

5. Verification / Validation

Confirm the fix by checking firewall rules and verifying that only authorized IP addresses can access the web interface. A smoke test ensures core functionality remains operational.

• Post-fix check: Use iptables -L INPUT to verify the new firewall rule is in place.
• Re-test: Attempt to access the Ansible Tower WebUI from an unauthorized IP address; the connection should be blocked.
• Smoke test: Log in to the Ansible Tower web interface with a valid user account and run a simple playbook.

iptables -L INPUT

6. Preventive Measures and Monitoring

Update security baselines and implement checks in CI/CD pipelines to prevent similar issues from occurring. A regular patch cycle ensures vulnerabilities are addressed promptly.

• Baselines: Update your security baseline or policy to require restricted access to web interfaces.
• Pipelines: Add a check in your CI/CD pipeline to scan for open ports and unauthorized network connections.
• Asset and patch process: Implement a regular patch cycle for Ansible Tower, ideally within 30 days of release.

7. Risks, Side Effects, and Roll Back

Restricting access could disrupt legitimate users if the firewall rules are misconfigured. A roll back involves restoring the original firewall configuration.

• Roll back: Restore the previous firewall configuration from a backup or snapshot.

8. References and Resources

• Vendor advisory or bulletin: https://www.ansible.com/products/tower