Security Experts:

Unpatched D-Link Router Vulnerabilities Disclosed

A researcher has disclosed the details of several unpatched vulnerabilities affecting D-Link DIR-850L routers and mydlink cloud services.

Researcher Pierre Kim has decided to make his findings public without giving D-Link time to release fixes due to the way the company handled patching and coordination for previously reported vulnerabilities.

“Their previous lack of consideration about security made me publish this research without coordinated disclosure,” Kim explained.

The expert discovered in mid-June that both revisions A and B of the DIR-850L firmware lack proper protection. The former allows an attacker to easily forge a firmware image, while the latter is protected with a hardcoded password.D-Link DIR-850L router vulnerability

He also found several cross-site scripting (XSS) vulnerabilities that can be exploited to steal authentication cookies from logged-in users. Hackers could also exploit various flaws to change a router’s DNS settings and forward the victim’s traffic to a malicious server, cause some services to enter a denial-of-service (DoS) condition, and execute arbitrary commands as root via the DHCP client.

Vulnerabilities identified by Kim in the mydlink cloud service, which allows users to access their D-Link devices from anywhere over the Internet, can be exploited by an unauthenticated hacker to remotely associate a targeted device with their own mydlink account, obtain device passwords -- which are in many cases stored or transmitted in clear text -- and take complete control of the router.

Kim believes the vulnerabilities related to the cloud service could also affect other D-Link products, including network-attached storage (NAS) devices and cameras. The expert has published detailed technical information for each of the security holes he found.

SecurityWeek has reached out to D-Link for comment and will update this article if the company responds.

D-Link recently patched three vulnerabilities found in DIR-850L routers by Kim and two other researchers as part of a hacking competition called Hack2Win. The flaws disclosed this week by the expert were not submitted to the contest, which only covered revision A of the router firmware.

UPDATE 09/12/2017. D-Link told SecurityWeek it became aware of the vulnerabilities on September 8, when the researcher made his findings public. 

"D-Link immediately took actions to investigate the issues and endeavors to solve them. A firmware update will be provided as soon as it becomes available via," the company said.

UPDATE 09/22/2017. D-Link has released firmware updates that patch most of these flaws.

Related: Vulnerabilities, Backdoors Found in D-Link Mobile Hotspot

Related: D-Link Failed to Patch HNAP Flaws in Routers

Related: D-Link Patches Critical Flaw in DIR Routers

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.