FortinacApplication · Fortinet
CVE-2020-12816
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 · uneditedAn improper neutralization of input vulnerability in FortiNAC before 8.7.2 may allow a remote authenticated attacker to perform a stored cross site scripting attack (XSS) via the UserID of Admin Users.
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 confidenceA stored cross-site scripting (XSS) vulnerability in FortiNAC versions before 8.7.2 allows an authenticated remote attacker to inject malicious JavaScript code through the UserID field when creating or modifying Admin Users. The injected payload executes in the browsers of other administrators who view the admin user management interface.
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
FortinacApplication
< 8.7.3CVSS 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
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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.
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Confirm FortiNAC is deployed in your environmentIdentify FortiNAC installations by checking for FortiNAC Control Center, FortiNAC portal services, or FortiNAC servers on your network. Look for the FortiNAC web interface (typically on port 8443 or 8080) or check running services on known FortiNAC hosts.Affected if FortiNAC software is not present in your environment, you are not affected.
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Determine the installed FortiNAC versionLog into the FortiNAC administrative interface (FortiNAC Control Center or direct FortiNAC access). Navigate to System > Settings > General or use the CLI command 'get system status' to retrieve the firmware version. Compare the version number against the affected range (versions before 8.7.3).Affected if The installed version is 8.7.2 or earlier, or any version below 8.7.3, indicating the vulnerability exists in your environment.
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Verify admin user management feature is accessibleConfirm you have access to the Admin User management interface within FortiNAC. Navigate to System > Administrator > Administrators or similar path depending on your version. This feature must be available and accessible for the XSS to be exploitable.Affected if The admin user management interface is not accessible or does not exist in your deployment, the specific attack vector is not applicable.
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Inspect existing admin UserID fields for suspicious contentReview all admin user accounts in the Administrator list. Examine the 'UserID' or 'Username' fields for any unexpected characters, scripts, or patterns such as '<script>', 'javascript:', or HTML tags that could indicate a previously injected payload.Affected if Any admin user account displays a UserID containing script tags, JavaScript event handlers, or other XSS payloads, indicating active exploitation or prior injection.
You are affected if FortiNAC version 8.7.2 or earlier (below 8.7.3) is installed AND the admin user management interface is accessible in your environment.
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 data8.7.3
Upgrade FortiNAC to version 8.7.2 or later to receive the vendor patch. Alternatively, apply the specific Fortinet hotfix if available, and implement input validation/sanitization on the UserID field as a defense-in-depth measure.
Fix this in Fortinac
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-12816 — 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-2020-12816 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
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