Rv016 Multi Wan Vpn Router FirmwareOperating system · Cisco
CVE-2021-1323
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 vulnerabilities in the web-based management interface of Cisco Small Business RV series routers allow authenticated attackers to send crafted HTTP requests and either execute arbitrary code with root privileges on the underlying OS or cause an unexpected device reload resulting in denial of service.
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
Rv016 Multi Wan Vpn Router FirmwareOperating system
<= 4.2.3.14
Rv042 Dual Wan Vpn Router FirmwareOperating system
<= 4.2.3.14
Rv042g Dual Gigabit Wan Vpn Router FirmwareOperating system
<= 4.2.3.14
Rv082 Dual Wan Vpn Router FirmwareOperating system
<= 4.2.3.14
Rv320 Dual Gigabit Wan Vpn Router FirmwareOperating system
<= 1.5.1.11
Rv325 Dual Gigabit Wan Vpn Router FirmwareOperating system
<= 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 device's web management interface and locate the System Summary or Status page, or use the command line interface (CLI) and run 'show version' to display the hardware model name (e.g., RV016, RV042, RV042g, RV082, RV320, or RV325).Affected if The model is one of the six affected models: RV016, RV042, RV042g, RV082, RV320, or RV325.
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Check the installed firmware versionIn the web interface, go to System Summary or Administration > Firmware Upgrade to view the current firmware version. Alternatively, via CLI run 'show version' which displays the firmware build number.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 if web-based management interface is enabledIn the web interface, navigate to Administration > Management or Security > Access Rules to confirm whether the HTTP/HTTPS management interface is enabled. Check which interfaces (LAN, WAN, or both) have management access permitted.Affected if The web-based management interface is enabled, particularly if it is accessible from the WAN interface.
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Review administrator accounts for unauthorized changesIn the web interface, go to Administration > User Accounts or AAA > Users to list all configured administrative accounts. Compare against known, documented accounts and look for any unfamiliar usernames, especially those with privilege level 15 (full admin).Affected if There are unexpected or unauthorized administrator accounts present, or if existing accounts have altered privilege levels.
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Check for unexpected system changes or processesIf CLI access is available, run 'show processes' or 'show system status' to look for unfamiliar processes. Review system logs (/var/log/messages or via the web interface Logs) for suspicious HTTP requests, particularly to CGI endpoints or unusual command injection patterns.Affected if There are unexpected processes, unexplained configuration changes, or suspicious log entries indicating arbitrary code execution attempts.
A user is affected if they are running any of the six listed router models with firmware at or below the specified version limits and the web management interface is enabled, especially if admin accounts have been modified without authorization.
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 the vendor-supplied firmware patch from Cisco. Since administrator credentials are required for exploitation, immediately rotate all admin passwords and review/administrative accounts for any unauthorized changes. Consider network segmentation to limit management interface exposure.
Fix this in Rv016 Multi Wan Vpn Router Firmware
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 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 $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1323 — 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-2021-1323 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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