CVE-2019-9509
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 · uneditedThe web interface of the Vertiv Avocent UMG-4000 version 4.2.1.19 is vulnerable to reflected XSS in an HTTP POST parameter. The web application does not neutralize user-controllable input before displaying to users in a web page, which could allow a remote attacker authenticated with a user account to execute arbitrary code.
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 · moderate confidenceReflected XSS vulnerability in the Vertiv Avocent UMG-4000 version 4.2.1.19 web interface. User-controllable input in an HTTP POST parameter is not neutralized before being rendered in web pages, allowing authenticated remote attackers to inject arbitrary JavaScript code.
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= 4.2.1.19CVSS 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
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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.
-
Identify the device modelAccess the web interface or check the device label/documentation to confirm it is a Vertiv Avocent UMG-4000 unit. The vulnerability applies only to this specific hardware model.Affected if The device is NOT a Vertiv Avocent UMG-4000 model.
-
Check the firmware versionLog into the UMG-4000 web interface and navigate to the firmware or system information page, or use the command-line interface to run 'show version' or similar command to retrieve the installed firmware version.Affected if The installed firmware version is NOT exactly 4.2.1.19.
-
Verify the web interface is enabledAttempt to access the UMG-4000 web interface via HTTP/HTTPS on the default ports (typically 80 or 443) or check the device network configuration to confirm the web service is active.Affected if The web interface is disabled and not accessible.
-
Confirm authentication is configuredCheck if local user accounts or authentication methods (local database, LDAP, etc.) are configured on the UMG-4000. This can be done via the web interface user management section or by reviewing the device configuration.Affected if No authentication methods are configured and no users exist on the system.
You are affected if your device is a Vertiv Avocent UMG-4000 running firmware version 4.2.1.19, the web interface is accessible, and user authentication is enabled or configurable.
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 proper input validation and output encoding for all user-supplied data in HTTP POST parameters. Apply vendor-supplied patch if available.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 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 $3,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-9509 — 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-2019-9509 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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