CVE-2021-27104
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 · uneditedAccellion FTA 9_12_370 and earlier is affected by OS command execution via a crafted POST request to various admin endpoints. The fixed version is FTA_9_12_380 and later.
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 confidenceAccellion File Transfer Appliance (FTA) versions 9_12_370 and earlier contains a critical OS command injection vulnerability. Attackers can execute arbitrary operating system commands by sending crafted POST requests to various admin endpoints, potentially gaining full control of the affected system.
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<= 9_12_370CVSS 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
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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 Accellion FTA installationCheck for running Accellion FTA processes or services on the system. Look for FTA-related web services on common ports (80, 443, 8443). Use commands like 'ps aux | grep -i accellion' or network scans for FTA banners.Affected if Accellion FTA software is installed and running on the system
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Determine FTA version numberAccess the FTA admin interface or check version files on the appliance. The version is typically displayed in the admin dashboard or can be retrieved via command line tools provided by FTA.Affected if The installed version is 9_12_370 or any version number lower than 9_12_370
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Verify admin endpoint exposureCheck network configuration to determine if FTA admin endpoints are accessible from the network. Review firewall rules and access control lists restricting access to admin interfaces.Affected if FTA admin endpoints (POST request handlers) are reachable from untrusted networks or the internet
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Check for indicators of compromiseReview FTA server logs for suspicious POST requests to admin endpoints, especially those containing shell metacharacters or unusual command patterns. Look for unexpected processes or files created after the software installation date.Affected if Log analysis reveals suspicious POST requests to admin endpoints or unexpected system modifications
You are affected if Accellion FTA versions 9_12_370 or earlier are installed and their admin endpoints are accessible, regardless of whether compromise has occurred.
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.
dbcve · scopedUpgrade Accellion FTA to version FTA_9_12_380 or later to remediate this vulnerability. Additionally, restrict network access to admin interfaces and monitor for suspicious administrative activity until the patch can be applied.
FTA_9_12_380 or later
- 1. Back up the Accellion FTA current installation, configuration, and all data before initiating the upgrade.
- 2. Download FTA_9_12_380 or later from the official Accellion support portal or authorized distribution channel.
- 3. Follow Accellion's official upgrade documentation for applying the patch to your FTA installation.
- 4. After upgrade completion, verify the FTA service is running properly.
- 5. Test that the admin endpoints are functioning correctly and the vulnerability is no longer present.
- 6. Review Accellion's additional security recommendations and apply any post-upgrade hardening steps.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-27104 — 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-2021-27104 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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