How to remediate – X-format Communications Protocol (XCP) Detection

1. Introduction

The X-format Communications Protocol (XCP) Detection vulnerability means a service monitoring Eaton and Powerware UPS devices is accessible remotely. This could allow an attacker to gather information about your power infrastructure, potentially disrupting operations. Systems running Eaton Intelligent Power Manager or similar UPS management software are usually affected. Impact on confidentiality is likely low but availability could be impacted if the service is abused.

2. Technical Explanation

The remote service supports XCP, a protocol used for communication with UPS devices. This protocol isn’t always secured by default, leaving it open to external access. An attacker can connect to this port and query information about the connected UPS. There is no known CVE associated with this specific detection but similar issues exist. For example, an attacker could use a simple telnet connection to enumerate device details.

• Root cause: The XCP service listens on a remote port without sufficient access controls.
• Exploit mechanism: An attacker connects to the exposed port and uses XCP commands to gather information about the UPS, potentially leading to denial of service or further exploitation. A simple example is connecting via telnet to the port and sending basic XCP query commands.
• Scope: Eaton Intelligent Power Manager (IPM) and other software using XCP for UPS communication are affected. Specific versions depend on configuration.

3. Detection and Assessment

You can confirm if a system is vulnerable by checking for the listening service or scanning the relevant port. A thorough method involves network traffic analysis.

• Quick checks: Use netstat -an | grep to see if anything is listening on the XCP port (typically 23).
• Scanning: Nessus vulnerability ID c5b90702 can detect this issue. This is an example only, and other scanners may also identify it.
• Logs and evidence: Check firewall logs for connections to the XCP port from unexpected sources. Event logs on the server running IPM might show connection attempts.

netstat -an | grep 23

4. Solution / Remediation Steps

Limit access to the XCP port to prevent unauthorised connections.

4.1 Preparation

• Dependencies: Ensure you have administrator access to the firewall and/or server running IPM. Rollback involves restoring the backup or reverting firewall rules.
• Change window: A standard change window may be required depending on your organisation’s policies. Approval from a senior IT manager might be needed.

4.2 Implementation

1. Step 1: Configure the firewall to allow connections to the XCP port only from trusted internal IP addresses or networks.
2. Step 2: Verify that external access to the XCP port is blocked by attempting a connection from an untrusted network.

4.3 Config or Code Example

Before

#Example firewall rule - allowing all connections on port 23 (XCP)
iptables -A INPUT -p tcp --dport 23 -j ACCEPT

After

#Example firewall rule - allowing only internal network access on port 23 (XCP)
iptables -A INPUT -s 192.168.1.0/24 -p tcp --dport 23 -j ACCEPT
iptables -A INPUT -p tcp --dport 23 -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 – restrict network access to services based on the principle of least privilege.
• Practice 2: Network segmentation – isolate critical systems like UPS management servers from untrusted networks.

4.5 Automation (Optional)

#Example Ansible playbook snippet to restrict XCP port access
- name: Restrict XCP Port Access
  iptables:
    chain: INPUT
    protocol: tcp
    dport: 23
    jump: DROP
    state: present

5. Verification / Validation

Confirm the fix by checking firewall rules and attempting a connection from an untrusted network.

• Post-fix check: Use iptables -L INPUT | grep 23 to verify that only trusted IP addresses are allowed access on port 23.
• Re-test: Re-run the initial netstat -an | grep command and confirm no external connections are established.
• Smoke test: Verify that IPM can still communicate with connected UPS devices from trusted internal networks.
• Monitoring: Monitor firewall logs for blocked connection attempts to port 23 from untrusted sources as an example of regression detection.

iptables -L INPUT | grep 23

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 your network security baseline to include rules restricting access to unnecessary ports like XCP.
• Pipelines: Implement infrastructure-as-code (IaC) scanning to automatically detect open ports in new deployments.
• Asset and patch process: Regularly review the configuration of critical systems for unexpected or insecure settings.

7. Risks, Side Effects, and Roll Back

• Roll back: Restore the previous firewall configuration or revert the snapshot taken during preparation.

8. References and Resources

• Vendor advisory or bulletin: http://www.nessus.org/u?c5b90702