How to remediate – EMC Legato Networker Detection

1. Introduction

EMC Legato Networker Detection indicates that backup software is running on a port. This software, used for data protection, can introduce risks if it’s outdated or misconfigured. It affects servers and virtual machines using EMC Legato Networker, Sun StorEdge Enterprise Backup Software, Sun Solstice Backup Software, or Informix Storage Manager. A compromised system could lead to data loss, unauthorized access, or service disruption. Confidentiality, integrity, and availability may be impacted.

2. Technical Explanation

The vulnerability stems from running backup software on a network port, which can expose services with known vulnerabilities. Attackers exploit these services remotely to gain control of the system. Preconditions include network access to the affected port and vulnerable versions of the software. An attacker could potentially execute arbitrary code or steal sensitive data by exploiting flaws in the Networker service.

• Root cause: The remote host is running a backup software package with potential vulnerabilities exposed on a network port.
• Exploit mechanism: Attackers scan for open ports and attempt to exploit known weaknesses in the Networker service, potentially gaining shell access or executing malicious code.
• Scope: Affected platforms include servers running EMC Legato Networker, Sun StorEdge Enterprise Backup Software, Sun Solstice Backup Software, and Informix Storage Manager.

3. Detection and Assessment

Confirming the presence of the software is the first step in assessing vulnerability. A quick check can identify if the service is running, while a thorough method involves checking version details.

• Quick checks: Use the command `netstat -tulnp | grep networker` to see if Networker processes are listening on any ports.
• Scanning: Nessus or OpenVAS may have plugins for detecting EMC Legato Networker; check their latest plugin sets. These are examples only.
• Logs and evidence: Check system logs (e.g., `/var/log/syslog` on Linux, Event Viewer on Windows) for entries related to the Networker service or associated processes.

netstat -tulnp | grep networker

4. Solution / Remediation Steps

The primary solution is to disable the unnecessary service or filter incoming traffic to the port.

4.1 Preparation

• Services: Stop the Networker service if it’s not required.
• Dependencies: Ensure stopping the service doesn’t impact critical applications. Roll back by restarting the service if needed.
• Change window: A standard change window may be appropriate, depending on your environment and risk tolerance.

4.2 Implementation

1. Step 1: Stop the Networker service using `systemctl stop networker` (Linux) or Services.msc (Windows).
2. Step 2: Disable the service to prevent automatic restarts with `systemctl disable networker` (Linux) or set Startup type to Disabled in Services.msc (Windows).
3. Step 3: If the service is required, configure firewall rules to restrict access to only authorized IP addresses and ports.

4.3 Config or Code Example

Before

systemctl status networker

After

systemctl status networker 
● networker.service - EMC Legato Networker
   Inactive (dead)

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this type of issue.

• Practice 1: Least privilege – Run services with the minimum necessary permissions to reduce impact if exploited.
• Practice 2: Network segmentation – Isolate critical systems and limit network access to only authorized users and devices.

4.5 Automation (Optional)

# Example Bash script to disable Networker service on Linux systems
#!/bin/bash
for host in $(cat /path/to/hostlist); do
  ssh $host "sudo systemctl stop networker && sudo systemctl disable networker"
done

5. Verification / Validation

Confirm the fix by checking service status and re-running detection methods.

• Post-fix check: Run `systemctl status networker` (Linux) or check Services.msc (Windows). The service should be inactive/disabled.
• Re-test: Re-run `netstat -tulnp | grep networker`. No Networker processes should be listening on any ports.
• Monitoring: Monitor system logs for unexpected errors related to the Networker service or associated processes.

systemctl status networker 
● networker.service - EMC Legato Networker
   Inactive (dead)

6. Preventive Measures and Monitoring

Update security baselines and implement checks in CI/CD pipelines to prevent similar issues.

• Baselines: Update your system hardening baseline to include disabling unnecessary services like Networker, or configuring firewall rules.
• Pipelines: Add a check in your CI/CD pipeline to scan for running backup software on network ports and flag any instances.
• Asset and patch process: Implement a regular review cycle for installed software and ensure timely patching of known vulnerabilities.

7. Risks, Side Effects, and Roll Back

Disabling the Networker service may impact data backups if it’s still in use.

• Risk or side effect 1: Data backup failure – If the service is required for backups, disabling it will cause backups to fail.
• Roll back: Restart the Networker service using `systemctl start networker` (Linux) or Services.msc (Windows).

8. References and Resources

• Vendor advisory or bulletin: No specific vendor advisory found for general detection, refer to EMC/Dell documentation.
• NVD or CVE entry: Not applicable as this is a detection of running software, not a specific vulnerability.
• Product or platform documentation relevant to the fix: Dell Networker Documentation