dbcve.org
CellsApplication · Pydio

CVE-2021-41323

MEDIUM · 6.5 CVSS v3.1 Published 2021-09-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

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
Directory traversal in the Compress feature in Pydio Cells 2.2.9 allows remote authenticated users to overwrite personal files, or Cells files belonging to any user, via the format parameter.

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 confidence

A directory traversal vulnerability exists in the Compress feature of Pydio Cells 2.2.9. The format parameter in the compress functionality does not properly sanitize path traversal sequences, allowing authenticated remote users to manipulate the parameter to navigate outside the intended directory and overwrite files belonging to other users or in protected locations.

MitigationImplement strict input validation on the format parameter to reject directory traversal sequences (../, ..\). Apply proper path sanitization ensuring the compressed output stays within the user's authorized directory. Consider updating to a patched version if available from the vendor.

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
CellsApplication
Affected:= 2.2.9

CVSS 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
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Pydio Cells version
    Check the Pydio Cells installation by looking at the admin dashboard under 'System Information' or run: cells --version from the command line if you have CLI access. You can also check the Docker container or package manager installation logs.
    Affected if The installed version is exactly 2.2.9 (note: only this specific version is affected)
  2. Confirm Compress feature is enabled
    Log into Pydio Cells as an authenticated user and verify the Compress/Zip functionality is available in the file operations menu. Check the plugin configuration at: Settings > Core > pydio.gateway.keep the zip plugin enabled.
    Affected if The Compress feature is accessible to authenticated users in the deployment
  3. Review access logs for path traversal patterns
    Examine Pydio Cells access logs (typically in /var/log/cells.log or via the admin console) for suspicious requests containing '../' or '..\' in the format parameter during compress operations. Search for entries matching patterns like: 'format=..%2F..%2F' or 'format=..\'
    Affected if Any compress requests contain directory traversal sequences in the format parameter
  4. Check for unauthorized file writes outside user directories
    Review the data directory (typically /data or the configured PYDIO_DATAS_PATH) for files created in unexpected locations. Compare timestamps against known compress operations. Look for zip files in /, /tmp, or other system directories.
    Affected if Files exist outside the expected user-specific data directory that were created during compress operations by authenticated users
  5. Audit user permissions and file ownership
    Run: ls -la on the Pydio data directory to inspect file ownership. Look for files owned by one user but created by another, or files in protected paths (etc, var, app data folders) that should not be writable by standard users.
    Affected if Files outside user home directories show unexpected ownership or permissions changes

You are affected if running Pydio Cells version 2.2.9 with the Compress feature enabled and you observe any directory traversal attempts in logs or unauthorized file writes outside user directories.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict input validation on the format parameter to reject directory traversal sequences (../, ..\). Apply proper path sanitization ensuring the compressed output stays within the user's authorized directory. Consider updating to a patched version if available from the vendor.

Fix this in Cells Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-41323 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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