CVE-2021-1347
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 · uneditedMultiple vulnerabilities in the web-based management interface of Cisco Small Business RV016, RV042, RV042G, RV082, RV320, and RV325 Routers could allow an authenticated, remote attacker to execute arbitrary code or cause an affected device to restart unexpectedly. These vulnerabilities are due to improper validation of user-supplied input in the web-based management interface. An attacker could exploit these vulnerabilities by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the device to reload, resulting in a denial of service (DoS) condition. To exploit these vulnerabilities, an attacker would need to have valid administrator credentials on the affected device.
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 confidenceMultiple input validation flaws in the web-based management interface of Cisco Small Business RV series routers (RV016, RV042, RV042G, RV082, RV320, RV325) allow authenticated remote attackers to send crafted HTTP requests that enable arbitrary code execution as root user on the underlying Linux-based operating system or cause device reload (DoS). The vulnerabilities stem from improper validation of user-supplied input in HTTP request parameters.
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<= 4.2.3.14<= 4.2.3.14<= 4.2.3.14<= 4.2.3.14<= 1.5.1.11<= 1.5.1.11CVSS 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
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/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 the router modelAccess the web-based management interface and locate the device model number typically displayed on the login page, in the header, or under Status > System Summary. Alternatively, physically inspect the device label or check the administrative console.Affected if The model is one of RV016, RV042, RV042G, RV082, RV320, or RV325.
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Check the firmware versionIn the web management interface, navigate to Status > System Summary or similar page that displays the firmware version. Note the exact version number displayed.Affected if The firmware version is at or below 4.2.3.14 for RV016/RV042/RV042G/RV082, or at or below 1.5.1.11 for RV320/RV325.
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Verify web management interface accessibilityConfirm that the web-based management interface is enabled and accessible. This can be verified by attempting to access the router's HTTP/HTTPS interface from a management station or reviewing the management access settings in the administration section.Affected if The web management interface is enabled and reachable (either locally or remotely).
A user is affected if they are running any of the affected RV series router models (RV016, RV042, RV042G, RV082, RV320, or RV325) with firmware at or below the specified version limits AND the web management interface is accessible.
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 Cisco-provided firmware updates for the affected router models. Until patches are available, restrict web management interface access to trusted networks only, enforce strong administrator credential policies, and monitor for anomalous HTTP requests.
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-1347 — 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-2021-1347 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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