Actively exploited vulnerability

D-Link DNS-320 Device: code execution flaw under attack

CVE-2020-25506 · D-Link DNS-320 Device Command Injection Vulnerability

Home network device9.8 critical

What is affected

D-Link DNS-320 Device is the kind of equipment many homes and small offices run for years without touching: a router, camera or storage box. Attackers scan the internet for exposed units, and a hijacked one can spy on traffic or be enrolled in a botnet without any visible sign.

D-Link DNS-320 device contains a command injection vulnerability in the sytem_mgr.cgi component that may allow for remote code execution.

CISA's description

What an attacker can do

This is a code execution flaw. It lets an attacker run their own commands or programs on the affected system. In practice that usually means taking it over: installing malware, stealing data or using it to reach other devices on the same network.

How it is reached
Over the internet or network
Access the attacker needs
No account needed
Does the victim have to do something?
No, works without the victim doing anything

What to do

  1. Check whether you own this device: look at the label on your router, camera or NAS, or open its admin page and note the model and firmware version.
  2. Install the latest firmware from the manufacturer's support page or the device's own update menu.
  3. If the manufacturer no longer releases updates for the model, replace it. An end-of-life device with an exploited flaw cannot be made safe.
  4. Turn off remote administration from the internet unless you truly need it, and change the default admin password.

Apply updates per vendor instructions.

Action required by CISA for US federal agencies

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on November 3, 2021, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by May 3, 2022, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 100% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 100.0% of all scored vulnerabilities.

Its CVSS severity score is 9.8 out of 10 (critical), as recorded in the US National Vulnerability Database.

Technical description

D-Link DNS-320 FW v2.06B01 Revision Ax is affected by command injection in the system_mgr.cgi component, which can lead to remote arbitrary code execution.

NIST National Vulnerability Database
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