Support Announcements
DSR-250 :: H/W Rev. Cx :: F/W v3.17B701C and below :: DMZ-enabled host on device is reachable by other host on LAN during boot sequence till DMZ feature is activated when boot is complete.




On September 9, 2021,  a 3rd party accused the DSR-250 hardware revision Cx (all C revisions) of a malfunctioning DMZ feature.  


The DMZ (Demilitarized Zone) feature is used to isolate a device on the DSR-250 from the rest of the local network and expose it directly to the internet. When you designate a device as the DMZ, all incoming traffic from the internet is directed to that specific device or network, bypassing any firewall or security measures in place. A key feature of the DMZ is Security Isolation: By placing a device in the DMZ, it is separated from the local network, which adds an extra layer of security. If that DMZ device was compromised, the rest of the devices on the DSR-250 local network would be protected to some extent.


The D-Link DSR-series is qualifed as a "Services Router" and has a flexable software based feature set allowing it to perform may different tasks needed for a Small Business network. One of the features is DMZ, and as reported it was found that during the devices sequence, untill the firmware was loaded, the device connected to the DMZ could be accessible to the LAN devices, which as defined is a violation of Security Isolation.


As soon as D-Link was made aware of the reported security issues, we started our investigation, confirmed the report, and began developing a fix.


D-Link released a Firmware for the device 3.18B001 on May 16, 202, linked below.


D-Link takes the issues of network security and user privacy very seriously. We have a dedicated task force and product management team on call to address evolving security issues and implement appropriate security measures.


Report information 


                - Contact via US Customer Care: D-Track: DUSA20220325000001

Affected Models


Model Hardware Revision  Region Affected FW Fixed FW Recommendation  Last Updated
DSR-250 All C Series Hardware Revisions WW v3.17B701C and below v3.18B001C Download & Update Device 05/26/2023


Regarding Security patch for your D-Link Devices
Firmware updates address the security vulnerabilities in affected D-Link devices. D-Link will update this continually and we strongly recommend all users to install the relevant updates.
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 provide 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.