CVE-2021-34978
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 R6260 1.1.0.78_1.0.1 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the setupwizard.cgi page. A crafted SOAP request can trigger an overflow of a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-13511.
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 confidenceUnauthenticated stack-based buffer overflow in NETGEAR R6260 router firmware (1.1.0.78_1.0.1) within the setupwizard.cgi component. A crafted SOAP request overflows a fixed-length stack buffer, enabling arbitrary code execution with root privileges. The attack is executable by network-adjacent attackers without authentication.
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= 1.1.0.78_1.0.1CVSS 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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Identify device modelAccess router admin panel or check device label to confirm the model is Netgear R6260Affected if Device is NOT a Netgear R6260, then not affected
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Check firmware versionLog into router web interface (typically at 192.168.1.1), navigate to Administration > Firmware Update or Advanced > Administration > Router Update to view current firmware versionAffected if Firmware version is exactly 1.1.0.78_1.0.1, then affected; if different version then not affected by this specific CVE
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Verify setupwizard.cgi accessibilityFrom a network-adjacent host, attempt to access http://<router-ip>/setupwizard.cgi or send a SOAP request to port 80/443 to confirm the endpoint is reachableAffected if The setupwizard.cgi endpoint responds to requests without authentication, indicating the vulnerable component is exposed
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Check management interface exposureDetermine if router management interface is accessible from WAN or untrusted networks by reviewing firewall rules or attempting access from external IPAffected if Router management interface (HTTP/HTTPS on ports 80/443) is accessible from network-adjacent untrusted hosts, increasing exploitability
You are affected if your Netgear R6260 runs firmware version 1.1.0.78_1.0.1 and the setupwizard.cgi component is accessible to network-adjacent attackers without authentication.
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 firmware patch when available; until then, restrict access to the router's management interface via network segmentation or firewall rules to minimize attack surface.
- Consultation4.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-34978 — 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-2021-34978 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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