CVE-2021-44880
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 · uneditedD-Link devices DIR_878 DIR_878_FW1.30B08_Hotfix_02 and DIR_882 DIR_882_FW1.30B06_Hotfix_02 were discovered to contain a command injection vulnerability in the system function. This vulnerability allows attackers to execute arbitrary commands via a crafted HNAP1 POST request.
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 confidenceD-Link DIR_878 and DIR_882 routers running specific hotfix firmware versions contain a command injection vulnerability in the system function. Attackers can execute arbitrary OS commands by sending a crafted HNAP1 POST request to the device, achieving unauthenticated remote code execution with critical severity (CVSS 9.8).
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<= 1.20b05= 1.30b08<= 1.30b06= 1.30b06CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify your D-Link router modelCheck the device label or web interface status page to confirm the exact model number (DIR_878 or DIR_882)Affected if The device is not a DIR_878 or DIR_882 model (different models are not affected by this specific CVE)
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Check the installed firmware versionLog into the router web interface, navigate to Status or Management > Firmware Upgrade, and record the firmware version shownAffected if Firmware version is 1.20b05 or earlier, or exactly 1.30b08 (for DIR_878); or 1.30b06 or earlier (for DIR_882)
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Confirm HNAP1 service is accessibleAttempt to access http://<router-ip>/HNAP1/ or check the router web interface for HNAP/HNAP1 settings. If the endpoint responds, the service is enabledAffected if HNAP1 is exposed and accessible on the network (this is the required attack surface for command injection)
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Verify the web management interface is reachableAttempt to access the router web interface on ports 80 or 443 from your local networkAffected if The router web interface is accessible (the vulnerability is exploited via crafted POST requests to this interface)
Your router is affected if it is a DIR_878 or DIR_882 model running an affected firmware version AND the HNAP1 web service is enabled and accessible on your network.
Generated from the published advisory. Verify against your own configuration.
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 dataApply vendor-supplied firmware patches when available; until then, restrict network access to the router's management interface using firewall rules or disable HNAP1 functionality if possible.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-44880 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-44880 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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