How to remediate – Cisco TelePresence Multipoint Switch Web Detection

1. Introduction

The Cisco TelePresence Multipoint Switch Web Detection vulnerability refers to the presence of a web management application hosted on a CTMS device. This is concerning because it exposes an administrative interface that could be targeted by attackers. Affected systems are typically Cisco TelePresence Multipoint Switches used in videoconferencing infrastructure, potentially impacting confidentiality, integrity and availability if compromised.

2. Technical Explanation

The vulnerability arises from the default installation of a web-based management application on CTMS devices. This application allows remote administration of the switch but may not have adequate security controls by default. An attacker could exploit this to gain unauthorized access to the CTMS device and modify its configuration or intercept video conferencing data. There is no specific CVE associated with this detection, as it represents a configuration issue rather than a software flaw. A realistic example would be an attacker gaining access to the web interface using default credentials (if not changed) and then altering routing configurations on the switch.

• Root cause: The web management application is enabled by default without strong security measures in place.
• Exploit mechanism: An attacker attempts to access the web interface, potentially using default or weak credentials. Successful login allows full administrative control of the CTMS device.
• Scope: Cisco TelePresence Multipoint Switches (CTMS).

3. Detection and Assessment

To confirm whether a system is vulnerable, first check for the presence of the web management application. A thorough method involves attempting to access the default web interface port.

• Quick checks: Use ping {CTMS IP address} to verify connectivity, then attempt to browse to the CTMS’s IP address on standard HTTP (port 80) and HTTPS (port 443) ports.
• Scanning: Nessus plugin ID 162795 can detect this issue. This is an example only; results may vary depending on scanner configuration.
• Logs and evidence: Check web server logs for access attempts to the CTMS IP address on ports 80 or 443.

ping {CTMS IP address}

4. Solution / Remediation Steps

The following steps provide a precise method to remediate this issue. These steps should be performed in a controlled environment.

4.1 Preparation

• Ensure you have console access or another method to restore the configuration if needed. A roll back plan is to restore from the previously created backup.
• A change window may be required, and approval from network administrators should be obtained.

4.2 Implementation

1. Step 1: Change the default password for the web management application. Use a strong, unique password.
2. Step 2: Implement access control lists (ACLs) to restrict access to the web interface to authorized IP addresses only.
3. Step 3: Consider disabling the web management application if it is not required.

4.3 Config or Code Example

Before

After

configure terminal
username admin password {strong_password} privilege 15
end
write memory

4.4 Security Practices Relevant to This Vulnerability

Several security practices directly address this vulnerability type. Least privilege reduces the impact if exploited, while strong passwords and access controls limit unauthorized access. Input validation can prevent malicious requests from being processed.

• Practice 1: Implement least privilege principles by granting only necessary permissions to users.
• Practice 2: Enforce strong password policies for all administrative accounts.

4.5 Automation (Optional)

Automation is not recommended due to the risk of misconfiguration. Manual changes are preferred in this case.

5. Verification / Validation

• Post-fix check: Attempt to log in to the web interface using the old default credentials; login should fail.
• Re-test: Repeat the earlier detection method (browsing to the CTMS IP address on ports 80/443) and confirm that access is restricted as expected.
• Monitoring: Monitor web server logs for unauthorized access attempts to the CTMS interface.

Attempt login with default credentials - should fail

6. Preventive Measures and Monitoring

• Baselines: Update a security baseline to require strong passwords and restrict access to administrative interfaces.
• Pipelines: Add checks in CI/CD pipelines to scan for default credentials or insecure configurations.
• Asset and patch process: Implement a regular review cycle for network device configurations.

7. Risks, Side Effects, and Roll Back

• Risk or side effect 2: Blocking legitimate users if access is restricted too narrowly. Mitigation: Carefully plan ACLs and document authorized IP addresses.
• Roll back: Restore the CTMS configuration from the backup created prior to making any changes.

8. References and Resources

Links only to sources that match this exact vulnerability.

• Vendor advisory or bulletin: https://www.cisco.com/c/en/us/products/conferencing/telepresence-multipoint-switch/index.html
• NVD or CVE entry: Not applicable, as this is a configuration issue.
• Product or platform documentation relevant to the fix: https://www.cisco.com/c/en/us/td/docs/telepresence/mps/configuration-guide/mps_config_guide.html