How to remediate – Cisco Prime Network / Wireless Control System Health Monitor D…

1. Introduction

The vulnerability is a detected web management interface for Cisco Prime Network / Wireless Control System Health Monitor. This interface manages high availability for Network/Wireless Control Systems and its presence indicates potential exposure of administrative functions to the network. Successful exploitation could allow unauthorized access to system configuration and monitoring data, impacting confidentiality, integrity, and availability.

2. Technical Explanation

The vulnerability stems from the unintentional exposure of a web interface used for managing high availability features within Cisco Prime Network / Wireless Control System Health Monitor. An attacker could exploit this by accessing the exposed interface to gain administrative control over the health monitoring system. No specific CVE is currently associated with this detection, but it represents a potential security risk due to the sensitive nature of the managed systems. A realistic example would be an attacker gaining access to the web interface and modifying high availability settings, potentially causing service disruption or data loss.

• Exploit mechanism: An attacker scans for open ports 80 or 443 on the target system and attempts to access the Health Monitor web interface. If successful, they can log in with default credentials (if unchanged) or attempt credential stuffing/brute-force attacks.
• Scope: Cisco Prime Network / Wireless Control System Health Monitor instances are affected.

3. Detection and Assessment

To confirm vulnerability, check for the presence of the web interface on the system. A quick check involves a simple port scan, followed by attempting to access the interface in a browser.

• Quick checks: Use `netstat -tulnp` or `ss -tulnp` to see if ports 80 or 443 are listening and associated with the Health Monitor process.
• Scanning: Nessus vulnerability scan ID 16729 can identify this issue as an example.
• Logs and evidence: Check system logs for access attempts to port 80 or 443 related to the Health Monitor service.

netstat -tulnp | grep :80

4. Solution / Remediation Steps

The following steps describe how to remediate this issue by disabling or securing the web interface.

4.1 Preparation

• Ensure you have access credentials for the Health Monitor system. A roll back plan involves restoring the backed-up configuration if needed.
• A change window may be required depending on organizational policies.

4.2 Implementation

1. Step 1: Log in to the Cisco Prime Network / Wireless Control System Health Monitor web interface.
2. Step 2: Navigate to Administration > Security Settings.
3. Step 3: Disable the web interface or restrict access via IP address filtering, limiting access to trusted networks only.

4.3 Config or Code Example

Before

Web Interface Enabled: Yes

After

Web Interface Enabled: No

4.4 Security Practices Relevant to This Vulnerability

Practices that directly address this vulnerability type include least privilege and secure defaults. Least privilege reduces the impact if the interface is compromised, while secure defaults prevent unnecessary exposure of sensitive services.

• Practice 1: Implement least privilege by restricting access to administrative interfaces only to authorized personnel.
• Practice 2: Enforce secure defaults by disabling unused or unnecessary services and features.

4.5 Automation (Optional)

Automation is not directly applicable for this vulnerability due to the configuration-based nature of the fix. However, infrastructure as code tools could be used to enforce consistent security settings across multiple Health Monitor instances.

5. Verification / Validation

Confirm the fix by verifying that the web interface is no longer accessible from untrusted networks. Re-run the earlier detection methods to confirm the issue is resolved.

• Post-fix check: Attempt to access the Health Monitor web interface in a browser from an untrusted network; it should be unreachable or display an error message.
• Re-test: Run `netstat -tulnp | grep :80` again, and confirm that port 80 is no longer listening or associated with the Health Monitor process if disabled.
• Smoke test: Verify that other core Health Monitor functions (e.g., high availability status monitoring) are still working as expected.
• Monitoring: Check system logs for failed access attempts to port 80 or 443, which could indicate ongoing reconnaissance activity.

netstat -tulnp | grep :80

6. Preventive Measures and Monitoring

Update security baselines to include disabling unused web interfaces. Implement checks in CI/CD pipelines to enforce consistent security configurations during deployment. A sensible patch or config review cycle of monthly is recommended.

• Baselines: Update a security baseline or policy to require disabling the Health Monitor web interface unless specifically required and properly secured.
• Pipelines: Add checks in CI/CD pipelines to verify that the Health Monitor web interface is disabled by default or configured with appropriate access controls.
• Asset and patch process: Implement a regular review cycle for system configurations to identify and remediate potential security vulnerabilities like exposed interfaces.

7. Risks, Side Effects, and Roll Back

Disabling the web interface may impact remote management capabilities if they rely on it. If this occurs, re-enable the interface with appropriate access controls.

• Risk or side effect 1: Disabling the web interface could disrupt remote management workflows that depend on it; ensure alternative management methods are available.
• Roll back: Re-enable the web interface in the Health Monitor configuration if needed, restoring the previous settings from the backup.

8. References and Resources

Links to sources that match this exact vulnerability.

• Vendor advisory or bulletin: http://www.nessus.org/u?d597bdf2
• NVD or CVE entry: Not applicable at this time.
• Product or platform documentation relevant to the fix: http://www.nessus.org/u?3885420a