CVE-2021-25630
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 · unedited"loolforkit" is a privileged program that is supposed to be run by a special, non-privileged "lool" user. Before doing anything else "loolforkit" checks, if it was invoked by the "lool" user, and refuses to run with privileges, if it's not the case. In the vulnerable version of "loolforkit" this check was wrong, so a normal user could start "loolforkit" and eventually get local root privileges.
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 confidenceloolforkit is a privileged setuid/setgid binary that requires execution by a specific non-privileged 'lool' user. The user verification check in the vulnerable version was incorrectly implemented, allowing any local user to invoke the binary and escalate privileges to root through the flawed permission validation.
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>= 4.2.0, < 4.2.13>= 6.4.0, < 6.4.3CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/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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Locate loolforkit binarySearch for the loolforkit binary on the system using 'find / -name loolforkit 2>/dev/null' or check common paths like /usr/bin/loolforkit, /opt/collaboraoffice*/bin/loolforkitAffected if The loolforkit binary exists on the system (vulnerable binary present)
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Verify binary permissionsRun 'ls -la <path_to_loolforkit>' to check if the file has setuid and/or setgid permissions (look for 's' in owner/group execute fields)Affected if The binary has setuid (owner root with s bit) or setgid (group root with s bit) permissions set, making it exploitable
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Check file ownershipRun 'ls -la <path_to_loolforkit>' to verify the binary is owned by rootAffected if The binary is owned by root and has elevated privileges
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Determine installed Collaboraoffice Online versionCheck the installed version via package manager (e.g., 'dpkg -l | grep -i collabora' or 'rpm -qa | grep -i collabora') or check version files in the installation directoryAffected if Installed version is >= 4.2.0 and < 4.2.13, OR >= 6.4.0 and < 6.4.3 (vulnerable version range)
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Verify lool user existenceCheck if the 'lool' user exists on the system using 'id lool' or 'grep ^lool: /etc/passwd'Affected if The lool user exists and the binary is configured to validate this user (exploitation requires the flawed check to be present)
A system is affected if the loolforkit binary exists with setuid/setgid permissions and the installed Collaboraoffice Online version falls within 4.2.0-4.2.12 or 6.4.0-6.4.2, allowing any local user to potentially escalate to root.
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 data4.2.136.4.3
Replace or patch loolforkit with a corrected version that properly validates the calling user is the designated 'lool' user before granting elevated privileges, or remove the binary if unnecessary.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-25630 — 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-2021-25630 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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