CVE-2019-20031
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 · uneditedNEC UM8000, UM4730 and prior non-InMail voicemail systems with all known software versions may permit an infinite number of login attempts in the telephone user interface (TUI), effectively allowing brute force attacks.
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 confidenceThe NEC UM8000, UM4730 and prior non-InMail voicemail systems contain an authentication bypass vulnerability in the telephone user interface (TUI). The system permits an infinite number of login attempts, allowing attackers to conduct unrestricted brute force attacks against voicemail accounts to discover valid credentials.
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 dataall versionsall versionsCVSS 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
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
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 NEC voicemail hardware modelLocate the voicemail system hardware or check system documentation to confirm the model is NEC UM8000 or UM4730 (or any prior non-InMail version)Affected if Model is confirmed as NEC UM8000 or UM4730 (or prior non-InMail) voicemail system
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Determine if telephone user interface is network accessibleCheck network configurations, firewall rules, or VoIP/Telephony infrastructure to see if the TUI port or service is exposed to network segmentsAffected if TUI is reachable from any network (especially untrusted or external networks)
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Check TUI login attempt controlsAccess the voicemail system admin interface or documentation to review login security settings for the telephone user interfaceAffected if No account lockout policy, rate limiting, or maximum failed attempt restriction is configured for TUI login
You are affected if your environment contains a NEC UM8000 or UM4730 voicemail system with an accessible TUI that permits unlimited login attempts.
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 dataImplement account lockout policies or rate limiting on the TUI login interface to restrict the number of failed attempts, or upgrade to a patched version if available. Consider network segmentation to limit exposure of the voicemail TUI to untrusted networks.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-20031 — 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-2019-20031 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
- No spam, self-promotion, credentials, or personal data