How to remediate – DLink DIR-610 Multiple Vulnerabilities

1. Introduction

The DLink DIR-610 Multiple Vulnerabilities affect a web application on this device. These vulnerabilities stem from unsupported software and allow remote command execution and information disclosure. This impacts the confidentiality, integrity, and availability of systems connected to the network where the router is deployed.

2. Technical Explanation

The DLink DIR-610 devices are affected by multiple vulnerabilities due to being unsupported. Specifically, remote command execution is possible via the cmd parameter in command.php and information disclosure can be achieved through getcfg.php. An attacker could execute arbitrary commands on a vulnerable device or access sensitive configuration data.

• Root cause: The DLink DIR-610 is no longer supported by the vendor, leaving known vulnerabilities unpatched.
• Exploit mechanism: An attacker can send crafted HTTP requests to command.php with a malicious payload in the cmd parameter or access sensitive information via getcfg.php. For example, sending a request like http://[target_ip]/command.php?cmd=whoami could reveal the user running the web server process.
• Scope: D-Link DIR-610 devices are affected. These vulnerabilities only affect products that are no longer supported by the maintainer.

3. Detection and Assessment

Confirming vulnerability requires checking the device’s firmware version. As Nessus relies on self-reported versions, this is the primary method of detection.

• Quick checks: Access the DLink DIR-610 web interface and check the “Firmware Version” under System Information.
• Scanning: Nessus vulnerability ID 243a769a can be used, but relies on self-reported version numbers.
• Logs and evidence: There are no specific logs to identify this vulnerability directly; however, unusual activity in web server access logs may indicate exploitation attempts.

4. Solution / Remediation Steps

The only effective solution is to retire and replace the vulnerable device, as it no longer receives security updates.

4.1 Preparation

• There are no dependencies; however, plan a change window to minimize disruption. A roll back plan involves not replacing the device and accepting the risk.
• Change windows should be planned with IT management approval due to the security implications of running an unsupported device.

4.2 Implementation

1. Step 1: Power off the DLink DIR-610.
2. Step 2: Disconnect the device from the network.
3. Step 3: Replace with a supported router from a reputable vendor.

4.3 Config or Code Example

No configuration changes are possible as the device is being retired.

Before

After

4.4 Security Practices Relevant to This Vulnerability

Maintaining a current patch cadence and using supported devices are critical for preventing this type of issue. Regularly review hardware lifecycles and replace end-of-life equipment.

• Practice 1: Patch management ensures timely updates, mitigating known vulnerabilities.
• Practice 2: Asset inventory helps identify unsupported or end-of-life devices that pose a security risk.

4.5 Automation (Optional)

Automation is not applicable for this remediation as the device is being retired.

5. Verification / Validation

Verification involves confirming the old device is removed from the network and the new router is functioning correctly.

• Post-fix check: Verify that the DLink DIR-610 is no longer present on the network (e.g., ping test fails).
• Re-test: No re-test is necessary as the device has been retired.
• Smoke test: Confirm internet connectivity and access to internal resources through the new router.
• Monitoring: Monitor network traffic for any unexpected activity originating from the replaced device’s IP address range (though it should be offline).

6. Preventive Measures and Monitoring

Preventive measures include maintaining a current asset inventory, establishing a patch management process for supported devices, and regularly reviewing hardware lifecycles. For example, implement a policy to replace end-of-life network equipment within 30 days of the vendor’s end-of-support date.

• Baselines: Update security baselines to include supported device models only.
• Pipelines: Implement checks in deployment pipelines to prevent unsupported devices from being added to the network.
• Asset and patch process: Conduct quarterly asset reviews to identify end-of-life hardware.

7. Risks, Side Effects, and Roll Back

• Risk or side effect 1: Temporary network outage during switchover. Mitigation: Plan change window during off-peak hours.
• Roll back: Step 1: Reconnect the DLink DIR-610 to the network. Step 2: Restore previous network settings (if known).

8. References and Resources

Links to official advisories are provided below.

• Vendor advisory or bulletin: http://www.nessus.org/u?243a769a
• NVD or CVE entry: CVE-2020-9376, CVE-2020-9377
• Product or platform documentation relevant to the fix: Not applicable as device is unsupported.