1. Introduction
The login page for a Cisco TelePresence Video Communication Server video conferencing device was detected on the remote web server. This indicates that the VCS web interface is accessible, potentially allowing attackers to extract version information with valid HTTP credentials. This could lead to reconnaissance and further exploitation of known vulnerabilities in specific versions. Confidentiality may be impacted through exposure of system details.
2. Technical Explanation
The vulnerability occurs because the VCS web interface is exposed on a network, allowing unauthenticated access to version information with valid credentials. An attacker can connect to the web UI and retrieve sensitive data about the device’s configuration and software versions. This information can then be used to identify known vulnerabilities and plan an attack.
- Root cause: The VCS web interface is accessible without proper restrictions, allowing version extraction with valid credentials.
- Exploit mechanism: An attacker connects to the exposed web UI using HTTP(S) and retrieves version information by accessing specific endpoints or pages.
- Scope: Cisco TelePresence Video Communication Server (VCS). Affected versions are not specified in this report.
3. Detection and Assessment
To confirm vulnerability, check for the presence of the VCS web interface on your network. A thorough method involves attempting to extract version information from the UI.
- Quick checks: Use a web browser to access the IP address or hostname of the suspected VCS device. Look for a login page associated with Cisco TelePresence Video Communication Server.
- Scanning: Nessus vulnerability ID 9d61b23d can be used as an example scanner query.
- Logs and evidence: Web server logs may show access attempts to the VCS web interface, indicating potential exposure.
# Example command placeholder:
# Use nmap or similar tool to scan for open ports associated with HTTP/HTTPS on suspected VCS devices.
# nmap -p 80,443
4. Solution / Remediation Steps
The following steps outline how to remediate the issue.
4.1 Preparation
- Change window needs and approval may be needed depending on your organization’s policies.
4.2 Implementation
- Step 1: Restrict access to the VCS web interface using firewall rules or network segmentation. Limit access only to authorized personnel.
- Step 2: If possible, disable the web interface if it is not required for administration.
4.3 Config or Code Example
Before
# No specific firewall rules restricting access to VCS web interface.
After
# Firewall rule blocking external access to port 80 and 443 for the VCS IP address, allowing only authorized IPs.
# Example: iptables -A INPUT -p tcp --dport 80 -s -j ACCEPT
# iptables -A INPUT -p tcp --dport 443 -s -j ACCEPT
# iptables -A INPUT -p tcp --dport 80 -j DROP
# iptables -A INPUT -p tcp --dport 443 -j DROP
4.4 Security Practices Relevant to This Vulnerability
List only practices that directly address this vulnerability type. Use neutral wording and examples instead of fixed advice. For example: least privilege, input validation, safe defaults, secure headers, patch cadence.
- Practice 1: Least privilege access control to reduce the impact if the web interface is compromised.
- Practice 2: Network segmentation to isolate sensitive systems and limit exposure.
4.5 Automation (Optional)
# Example Ansible playbook snippet to block access to VCS web interface:
# - name: Block external access to VCS web interface
# iptables:
# chain: INPUT
# protocol: tcp
# dport: '80,443'
# jump: DROP
# state: present
5. Verification / Validation
Confirm the fix by verifying that unauthorized access to the VCS web interface is blocked.
- Post-fix check: Attempt to access the VCS web interface from an unauthorized IP address. The connection should be refused or timed out.
- Re-test: Re-run the earlier detection method (web browser access) from an unauthorized IP address to confirm that the login page is no longer accessible.
- Smoke test: Verify that authorized users can still access other VCS services as needed.
- Monitoring: Monitor firewall logs for blocked connection attempts to port 80 and 443 on the VCS device.
# Post-fix command and expected output:
# telnet 80 - Connection refused or timeout.
6. Preventive Measures and Monitoring
Suggest only measures that are relevant to the vulnerability type. Use “for example” to keep advice conditional, not prescriptive.
- Baselines: Update security baselines with firewall rules restricting access to sensitive interfaces like VCS web UI.
- Pipelines: Implement infrastructure-as-code (IaC) scanning to detect exposed services during deployment.
- Asset and patch process: Maintain an inventory of all network devices and regularly review their configurations for unnecessary exposures.
7. Risks, Side Effects, and Roll Back
- Roll back: Remove the added firewall rules to restore original network connectivity.
8. References and Resources
- Vendor advisory or bulletin: http://www.nessus.org/u?9d61b23d