CVE-2020-27867
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 NETGEAR R6020, R6080, R6120, R6220, R6260, R6700v2, R6800, R6900v2, R7450, JNR3210, WNR2020, Nighthawk AC2100, and Nighthawk AC2400 routers. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the mini_httpd service, which listens on TCP port 80 by default. When parsing the funjsq_access_token parameter, 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 root. Was ZDI-CAN-11653.
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 the mini_httpd web service on NETGEAR routers (multiple models including R6020, R6080, R6120, R6220, R6260, R6700v2, R6800, R6900v2, R7450, JNR3210, WNR2020, Nighthawk AC2100/AC2400). The funjsq_access_token parameter is not validated before being used in a system call, allowing authenticated attackers (or those bypassing auth) to execute arbitrary code as root.
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< 1.2.0.76< 1.2.0.76< 1.2.0.76< 1.2.0.76< 1.2.0.76< 1.2.0.76< 1.2.0.76< 1.2.0.76CVSS 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
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/AC:L/PR:H/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 router modelAccess the router web interface or check the device label to confirm the exact model number (e.g., R6700, R6800, R6900, AC2100, AC2400, AC2600, R7200, R7350)Affected if The router model matches one of the affected models listed in the CVE (R6020, R6080, R6120, R6220, R6260, R6700v2, R6800, R6900v2, R7450, JNR3210, WNR2020, AC2100, AC2400, or the firmware versions listed)
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Check firmware versionLog into the router web interface and navigate to Administration > Firmware Update or check the current firmware version displayed in the status or settings pageAffected if The installed firmware version is lower than 1.2.0.76 for the affected models (Ac2100, Ac2400, Ac2600, R6700, R6800, R6900, R7200, R7350)
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Confirm mini_httpd service availabilityAttempt to access the router web interface via HTTP (port 80) or HTTPS (port 443) from the local networkAffected if The router web interface (mini_httpd) is accessible and responds to requests
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Verify remote management settingIn the router web interface, check Advanced > Remote Management or Administration > Remote Management to see if remote access over WAN is enabledAffected if Remote management is enabled, allowing potential attackers outside the local network to reach the vulnerable service
The router is affected if it is one of the listed models running firmware version lower than 1.2.0.76 and the mini_httpd web service is accessible (especially if remote management is enabled).
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 data1.2.0.76
Apply NETGEAR firmware updates when available; until then, restrict network access to router management interfaces using firewall rules or VLAN isolation, and disable remote management if enabled.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-27867 — 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-2020-27867 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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