Nginx ControllerWeb server / proxy · F5
CVE-2020-5909
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 · uneditedIn versions 3.0.0-3.5.0, 2.0.0-2.9.0, and 1.0.1, when users run the command displayed in NGINX Controller user interface (UI) to fetch the agent installer, the server TLS certificate is not verified.
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 confidenceIn NGINX Controller versions 1.0.1 through 3.5.0, the agent installer command displayed in the UI does not verify the server's TLS certificate when downloading the installer, allowing potential man-in-the-middle attackers to intercept and inject malicious code into the installation process.
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
Nginx ControllerWeb server / proxy
>= 2.0.0, <= 2.9.0>= 3.0.0, <= 3.5.0= 1.0.1CVSS 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
- Required
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/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 NGINX Controller versionAccess the NGINX Controller API at /api/v1/platform/version or check the UI footer for the version number. Alternatively, run: curl -k https://<controller-host>/api/v1/platform/versionAffected if The displayed version matches 1.0.1, or falls between 2.0.0-2.9.0, or falls between 3.0.0-3.5.0
-
Check for recent UI-based installer downloadsReview NGINX Controller access logs for requests to /api/v1/releases/agent or similar endpoints that serve the agent installer. Look for GET requests following UI session authentication.Affected if The controller has served agent installer packages to clients since deployment
-
Verify installer integrityIf agent installers were downloaded, locate the downloaded installer file and compute its SHA256 checksum. Compare against the checksum provided in the official NGINX Controller documentation for that version.Affected if The downloaded installer checksum does not match the official published checksum or no checksum was verified at download time
-
Inspect TLS verification configurationExamine the NGINX Controller configuration files under /etc/nginx-controller/ or the UI settings to confirm whether TLS certificate verification is enabled for the agent installer download mechanism.Affected if TLS certificate verification is disabled or not enforced for the installer download endpoint
You are affected if your NGINX Controller version is 1.0.1, between 2.0.0-2.9.0, or between 3.0.0-3.5.0 AND the agent installer was downloaded via the UI without checksum verification.
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 dataUpgrade NGINX Controller to a patched version. Until then, verify installer integrity through checksums and ensure downloads occur over trusted networks.
Fix this in Nginx Controller
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 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 $2,880.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5909 — 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-2020-5909 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