CVE-2021-27855
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 · uneditedFatPipe WARP, IPVPN, and MPVPN software prior to versions 10.1.2r60p91 and 10.2.2r42 allows a remote, authenticated attacker with read-only privileges to grant themselves administrative privileges. Older versions of FatPipe software may also be vulnerable. The FatPipe advisory identifier for this vulnerability is FPSA001.
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 confidenceThis is an authentication bypass/privilege escalation vulnerability in FatPipe WARP, IPVPN, and MPVPN. An authenticated user with only read-only privileges can escalate their own account to administrative level access, likely by manipulating API calls or session parameters that insufficiently validate authorization checks.
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= 5.2.0= 6.1.2= 7.1.2= 9.1.2= 10.1.2= 10.2.2= 5.2.0= 6.1.2= 7.1.2= 9.1.2= 10.1.2= 10.2.2= 5.2.0= 6.1.2= 7.1.2= 9.1.2= 10.1.2= 10.2.2CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 the FatPipe product in useLog into the FatPipe device web interface or check system documentation to determine if the deployed product is WARP, IPVPN, or MPVPNAffected if The product is FatPipe WARP, IPVPN, or MPVPN
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Check the installed firmware versionNavigate to the device web interface System Status or About page, or run 'version' or 'show system info' via CLI to retrieve the firmware versionAffected if The firmware version matches 5.2.0, 6.1.2, 7.1.2, 9.1.2, 10.1.2, or 10.2.2 exactly
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Identify read-only user accountsAccess the User Management or Accounts section in the web interface and list all defined users. Note which accounts have read-only or non-administrative privilegesAffected if Read-only or limited-privilege user accounts exist on the device
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Verify privilege assignment for read-only accountsReview the user role or privilege level assigned to each read-only account in the user management panel. Confirm whether the account has been silently elevated to administrative roleAffected if A read-only account has been modified to have administrator or full access privileges without explicit admin action
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Audit recent account privilege changesCheck system logs, audit logs, or account modification logs for any events where a read-only account was changed to an administrator roleAffected if Logs show unauthorized privilege escalation events on read-only accounts
You are affected if you are running FatPipe WARP, IPVPN, or MPVPN firmware version 5.2.0, 6.1.2, 7.1.2, 9.1.2, 10.1.2, or 10.2.2 and have read-only accounts that may have been silently elevated to administrative privileges.
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 FatPipe software to version 10.1.2r60p91, 10.2.2r42, or later per the vendor advisory FPSA001. If upgrades are not immediately possible, restrict read-only account access and monitor for unauthorized privilege changes.
Upgrade to FatPipe firmware 10.1.2r60p91 or 10.2.2r42
- 1. Identify the current FatPipe firmware version installed on the affected devices (IPVPN, Warp, or MPVPN).
- 2. Review the FatPipe device's current configuration and user accounts, noting any read-only users that may have unauthorized access.
- 3. Download the fixed firmware version 10.1.2r60p91 or 10.2.2r42 from the official FatPipe support portal at www.fatpipeinc.com.
- 4. Schedule a maintenance window for the firmware upgrade, ensuring minimal disruption to VPN services.
- 5. Upload and apply the new firmware to each affected FatPipe device following the vendor's standard upgrade procedure.
- 6. After upgrading, verify that the device is functioning correctly and that VPN tunnels are operational.
- 7. Review user account permissions to ensure the authorization fix is properly enforced - read-only users should no longer be able to escalate to administrative privileges.
- 8. Confirm the vulnerability is remediated by attempting to reproduce the privilege escalation with a read-only account (if in a test environment).
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 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-2021-27855 — 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-2021-27855 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
- No spam, self-promotion, credentials, or personal data