dbcve.org
Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 May 2022.
Dns 320 FirmwareOperating system · Dlink

CVE-2020-25506

CRITICAL · 9.8 CVSS v3.1 Published 2021-02-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
In the wild High EPSS Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The D-Link DNS-320 network attached storage device running firmware v2.06B01 contains a command injection vulnerability in the system_mgr.cgi web component. The vulnerability allows unauthenticated remote attackers to inject arbitrary OS commands through insufficient input validation, potentially executing them with root privileges on the underlying Linux-based firmware.

MitigationApply vendor firmware patches if available; if no patch exists, isolate the device on a restricted network segment or replace with a supported device. Implement web application firewall rules to detect and block suspicious requests to system_mgr.cgi.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Dns 320 FirmwareOperating system
Affected:= 2.06b01

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Access the device web interface or check the physical device label to confirm the model is D-Link DNS-320. Alternatively, check the DHCP lease table or network scan for the device's MAC OUI (D-Link) and hostname.
    Affected if Device model is not D-Link DNS-320
  2. Check firmware version
    Log into the device web interface and navigate to System > System Settings or similar. The firmware version is typically displayed on the status/dashboard page. For CLI access via SSH/Telnet, check the firmware version using the version command or cat /etc/version.
    Affected if Firmware version is exactly 2.06B01 (any Revision Ax)
  3. Verify web management interface is enabled
    Attempt to access the device's HTTP (port 80) or HTTPS (port 443) management interface from a browser. Confirm the login page or system_mgr.cgi responds.
    Affected if Web interface returns a 200 OK response and presents the D-Link login or CGI endpoint
  4. Confirm system_mgr.cgi is accessible
    Try accessing http://[device-ip]/cgi-bin/system_mgr.cgi directly in a browser. A valid response indicates the CGI script is exposed.
    Affected if system_mgr.cgi endpoint responds without authentication error or 404

User is affected if they have a D-Link DNS-320 running firmware version 2.06B01 with the web management interface and system_mgr.cgi component accessible on the network.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware patches if available; if no patch exists, isolate the device on a restricted network segment or replace with a supported device. Implement web application firewall rules to detect and block suspicious requests to system_mgr.cgi.

Fix this in Dns 320 Firmware Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,180
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,488.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-25506 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-25506 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data