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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 25 Apr 2022.
Dir 820l FirmwareOperating system · Dlink

CVE-2021-45382

CRITICAL · 9.8 CVSS v3.1 Published 2022-02-17
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
A Remote Command Execution (RCE) vulnerability exists in all series H/W revisions D-link DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-836L routers via the DDNS function in ncc2 binary file. Note: DIR-810L, DIR-820L, DIR-830L, DIR-826L, DIR-836L, all hardware revisions, have reached their End of Life ("EOL") /End of Service Life ("EOS") Life-Cycle and as such this issue will not be patched.

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

A Remote Command Execution (RCE) vulnerability exists in the DDNS function within the ncc2 binary file on multiple D-link router models (DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-836L). The vulnerability allows attackers to execute arbitrary commands on the affected devices without authentication.

MitigationSince these devices have reached End of Life and will not receive patches, the only remediation is to replace affected routers with supported models or implement network isolation to reduce exposure to external attack vectors.

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
Dir 820l FirmwareOperating system
Affected:all versions
Dir 820lw FirmwareOperating system
Affected:all versions
Dir 826l FirmwareOperating system
Affected:all versions
Dir 830l FirmwareOperating system
Affected:all versions
Dir 836l FirmwareOperating system
Affected:all versions
Dir 810l FirmwareOperating system
Affected:all versions

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 router web interface (typically 192.168.0.1) and check the status or system information page to confirm the exact model number (DIR-810L, DIR-820L, DIR-820LW, DIR-826L, DIR-830L, or DIR-836L). Alternatively, check the device label or packaging.
    Affected if The model is any of the following: DIR-810L, DIR-820L, DIR-820LW, DIR-826L, DIR-830L, or DIR-836L.
  2. Verify DDNS configuration
    Log into the router web interface and navigate to the DDNS settings page (usually under Advanced or Network Settings). Check whether DDNS is enabled and note the configured service provider and hostname.
    Affected if DDNS is enabled and configured on the device.
  3. Check DDNS service accessibility
    Determine if the router's DDNS management interface is exposed to the internet by checking port forwarding rules or firewall settings. Attempt to access the router's web interface from an external network on the typical management ports (80, 443, 8080).
    Affected if The router's management interface or DDNS service is accessible from the internet.
  4. Confirm ncc2 binary presence
    If you have shell access (via telnet, SSH, or serial console), check for the presence of the ncc2 binary by running: find / -name 'ncc2*' 2>/dev/null or ls -la /bin/ncc2 /usr/bin/ncc2 (paths may vary by firmware).
    Affected if The ncc2 binary exists on the device filesystem.

If the device model matches any of the affected D-Link routers (DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, DIR-836L) and DDNS is enabled or accessible, the environment is affected by this vulnerability.

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

Since these devices have reached End of Life and will not receive patches, the only remediation is to replace affected routers with supported models or implement network isolation to reduce exposure to external attack vectors.

Fix this in Dir 820l Firmware Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing2.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,900
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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-2021-45382 in production — separate from our analysis above.

No notes yet

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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