CVE-2021-31726
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 · uneditedAkuvox C315 115.116.2613 allows remote command Injection via the cfgd_server service. The attack vector is sending a payload to port 189 (default root 0.0.0.0).
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 confidenceA remote command injection vulnerability exists in the cfgd_server service of Akuvox C315 devices. An unauthenticated attacker can send malicious payloads to port 189 (which binds to 0.0.0.0, making it accessible from any network interface) to execute arbitrary operating system commands with root privileges. The CVSS 9.8 score indicates trivial exploitability with complete impact on confidentiality, integrity, and availability.
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= 115.116.2613CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/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 Akuvox C315 device modelCheck device model via web interface, system info page, or SSH login showing device identificationAffected if Device is not an Akuvox C315 (different models may have different vulnerabilities)
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Check firmware versionAccess device web interface System > System Info or use SSH to run 'cat /etc/version' or 'ver' command to retrieve firmware versionAffected if Firmware version is 115.116.2613 or if the specific version number cannot be determined but device is Akuvox C315
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Verify cfgd_server service is runningUse SSH to access device and run 'ps | grep cfgd_server' or check running servicesAffected if cfgd_server process is running on the device
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Confirm port 189 is listeningUse SSH to run 'netstat -tulpn | grep 189' or 'ss -tulpn | grep 189' to check if port 189 is bound and listeningAffected if Port 189 is open and bound to 0.0.0.0 (making it network-accessible)
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Check network accessibility of port 189From an external system, run 'nmap -p 189 <device_ip>' or 'nc -zv <device_ip> 189' to test if port 189 is reachable over the networkAffected if Port 189 is reachable from untrusted networks (not just localhost)
If the device is an Akuvox C315 with firmware version 115.116.2613 and port 189 is accessible over the network with cfgd_server running, the environment is affected by this vulnerability.
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 dataRestrict network access to port 189 via firewall rules or network segmentation to limit exposure. Contact Akuvox for firmware updates addressing this vulnerability; if unavailable, consider isolating affected devices on a dedicated VLAN with strict access controls.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-31726 — 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-2021-31726 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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