Advisory Details

This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of D-Link DIR-2055 routers. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the handling of HNAP login requests. The issue results from the lack of proper handling of empty passwords. An attacker can leverage this vulnerability to execute arbitrary code on the router.

This vulnerability is being disclosed publicly without a patch in accordance with the ZDI 120 day deadline.

03/31/21 – ZDI reported the vulnerabilities to the vendor/ICS-CERT
08/04/21 – ZDI requested an update
08/09/21 – The vendor indicated they would provide more details the following day
08/17/21 – The vendor indicated they were still waiting for updated details
08/18/20 – ZDI notified the vendor of the intention to publish the cases as 0-day advisories on 08/26/21

-- Mitigation:
Given the nature of the vulnerability the only salient mitigation strategy is to restrict interaction with the application.

• 2021-03-31 - Vulnerability reported to vendor
• 2021-08-26 - Coordinated public release of advisory