Overview

D-Link Corporation received a vulnerability report from CERT Polska regarding the default password generation mechanism on the D-Link DWR-X1820 router.

The report alleges that default passwords are generated using a predictable method derived from the last four digits of the device IMEI. D-Link has completed an internal technical review of this claim and provides the assessment below to ensure transparency and clarity for customers and partners.

At this time, D-Link does not classify this report as a confirmed security incident due to the absence of a demonstrated proof of concept capable of bypassing existing protections.

Report Information

• Reporting Entity: CERT Polska
• Reference ID: CERT.PL #5308494
• Date Received: January 15, 2026

• Report Summary:
  The reporter states that default passwords for the D-Link DWR-X1820 router are predictable and derived from the last four digits of the device IMEI, which could allow an attacker to determine the default credentials.

D-Link Technical Assessment

      Following internal investigation, D-Link confirms the following:

• The default password generation process uses the device IMEI combined with a random seed. This process produces a unique password per unit and does not rely solely on static or sequential IMEI digits.
• Access to the IMEI requires physical access to the device. Without physical access, external calculation of the default password is not feasible.
• Upon first login, the device enforces a mandatory password change with defined strength requirements. Device operation cannot proceed until this change occurs.
• The system enforces a lockout after three consecutive incorrect login attempts for a minimum of three minutes.

        Based on these controls, D-Link concludes that practical exploitability of the reported condition is

         negligible under normal operating conditions.

Current Status

• Classification: Not accepted as a confirmed security incident
• Reason: No proof of concept has been provided demonstrating successful defeat of existing protections or remote exploitability.
• Follow-up: D-Link acknowledges the report and will continue reviewing password generation mechanisms as part of ongoing security hardening efforts.

 Affected Product

Customer Guidance

D-Link recommends the following best practices for all supported networking products:

• Complete the mandatory password change during initial setup.
• Use strong, unique administrative passwords.
• Keep device firmware updated with the latest available release.
• Limit physical access to networking equipment.
• Enable all available security and access control features.

Please note that this is a device beta software, beta firmware, or hot-fix release, which is still undergoing final testing before its official release. The beta software, beta firmware, or hot-fix is provided on an “as is” and “as available” basis, and the user assumes all risk and liability for use thereof. D-Link does not offer any warranties, whether express or implied, as to the suitability or usability of the beta firmware. D-Link will not be liable for any loss, whether such loss is direct, indirect, special or consequential, suffered by any party as a result of their use of the beta firmware.

 As there are different hardware revisions on our products, please check this on your device before downloading the correct corresponding firmware update. The hardware revision information can usually be found on the product label on the underside of the product next to the serial number. Alternatively, they can also be found on the device web configuration.