D-Link firmware accidentally includes Code Signing Keys

The Taiwanese networking equipment manufacturer D-Link has accidentally published its private code signing keys in the source of one of its firmware update.

According to the Dutch news site Tweakers, the Taiwan-based networking equipment manufacturer D-Link accidently published its private code signing keys inside its open source firmware packages.

One of the readers of the Dutch news site reported, “bartvbl,”  reported the serious issues after he had bought a D-Link DCS-5020L security camera and downloaded the firmware from the official website of D-Link.

D-Link open sources its firmware under the GPL license allowing anyone to analyze it. bartvbl has discovered four different private keys used for code signing.

The reader also discovered other three private code signing keys that appear to be not valid and  pass-phrases needed to sign the software.

The disconcerting discovery was confirmed by the security expert Yonathan Klijnsma from security firm Fox-IT.

“The code signing certificate is indeed a firmware package, firmware version 1.00b03, who’s source was released February 27 this year,” explained the expert.

Why the access to the code signing keys is so important?

Malware creators use to steal valid code signing certificates to sign the source code of their malware and evade detection of security firms.


At the time I was writing, it is still unclear whether the code signing private keys have been used by threat actors to sign their malicious code signing certificate, and released a new version of the firmware that doesn’t contain any code signing keys.

Pierluigi Paganini

FAIR USE NOTICE: Under the "fair use" act, another author may make limited use of the original author's work without asking permission. Pursuant to 17 U.S. Code § 107, certain uses of copyrighted material "for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright." As a matter of policy, fair use is based on the belief that the public is entitled to freely use portions of copyrighted materials for purposes of commentary and criticism. The fair use privilege is perhaps the most significant limitation on a copyright owner's exclusive rights. Cyber Defense Media Group is a news reporting company, reporting cyber news, events, information and much more at no charge at our website Cyber Defense Magazine. All images and reporting are done exclusively under the Fair Use of the US copyright act.

Global InfoSec Awards 2022

We are in our 10th year, and these awards are incredibly well received – helping build buzz, customer awareness, sales and marketing growth opportunities, investment opportunities and so much more.


10th Anniversary Exclusive Top 100 CISO Conference & Innovators Showcase