CVE-2020-27864
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 · uneditedThis vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DAP-1860 firmware version 1.04B03 WiFi extenders. Authentication is not required to exploit this vulnerability. The specific flaw exists within the HNAP service, which listens on TCP port 80 by default. When parsing the Authorization request header, the process does not properly validate a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of the device. Was ZDI-CAN-10880.
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 confidenceCommand injection vulnerability in D-Link DAP-1860 WiFi extenders firmware 1.04B03. The HNAP service on TCP port 80 does not properly validate the Authorization request header before passing it to a system call, allowing unauthenticated network-adjacent attackers to execute arbitrary code with device privileges.
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<= 1.04b03CVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/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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Confirm device model is D-Link DAP-1860Access the device web interface or check the physical label on the device to verify the exact model numberAffected if Device is a D-Link DAP-1860 WiFi extender
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Check installed firmware versionLog into the DAP-1860 web management interface (typically at 192.168.0.1 or 192.168.1.1) and navigate to Status or System settings to view the firmware versionAffected if Firmware version is 1.04B03 or any version lower than 1.04B03
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Verify HNAP service is accessible on TCP port 80From a network-adjacent host, run 'nc -zv <device_ip> 80' or 'telnet <device_ip> 80' to confirm the HTTP service is listeningAffected if Port 80 is open and responding on the DAP-1860 device
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Confirm HNAP endpoint is exposedSend an HTTP request to the device: 'curl -v http://<device_ip>/HNAP1/' or check if the HNAP1 SOAP endpoint respondsAffected if The HNAP1 endpoint returns a valid HTTP response (even if authentication is required)
You are affected if you have a D-Link DAP-1860 device running firmware version 1.04B03 or earlier with the HNAP service accessible on port 80.
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 dataSince the DAP-1860 is an end-of-life device with no security updates, replace with a supported device or implement network segmentation to limit exposure. If vendor firmware update exists, apply immediately.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2020-27864 — 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-2020-27864 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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- Version or environment caveats, and links to real fixes
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