CVE-2021-26622
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 remote code execution vulnerability due to SSTI vulnerability and insufficient file name parameter validation was discovered in Genian NAC. Remote attackers are able to execute arbitrary malicious code with SYSTEM privileges on all connected nodes in NAC through this vulnerability.
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 Server-Side Template Injection (SSTI) vulnerability combined with insufficient file name parameter validation in Genian NAC allows remote unauthenticated attackers to inject and execute arbitrary code with SYSTEM-level privileges on the NAC server, potentially affecting all connected nodes.
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>= 4.0, <= 4.0.145.0831>= 5.0, <= 5.0.42.0827CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 Genian NAC installationLocate the Genian NAC installation directory or check running services for 'Genian' or 'nac' processes on the server.Affected if Genian NAC software is present on the system
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Determine installed versionCheck the Genian NAC web interface login page footer, or look for version information in installation files, registry entries, or the service management console.Affected if Version number falls within 4.0 to 4.0.145.0831 or 5.0 to 5.0.42.0827 inclusive
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Assess management interface exposureReview firewall rules, network configuration, or reverse proxy settings to determine if the NAC management web interface (typically ports 443, 8443, or 8080) is accessible from untrusted network segments or the public internet.Affected if Management interface is reachable from untrusted IP addresses or the internet
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Check for unauthorized access indicatorsReview NAC server logs, especially authentication and file upload logs, for suspicious requests containing template syntax characters (such as {{, <%, #{ or file parameter anomalies that may indicate exploitation attempts.Affected if Logs show unexpected template injection patterns or anomalous file name parameter submissions
A system is affected if Genian NAC versions 4.0 through 4.0.145.0831 or 5.0 through 5.0.42.0827 are running with their management interface accessible to untrusted networks.
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 dataApply vendor-supplied patch immediately; if unavailable, restrict network access to the NAC management interface to trusted IPs only and implement strict input validation on all file name parameters.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 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 $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-26622 — 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-2021-26622 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
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