OnlineApplication · Collabora

CVE-2021-32744

HIGH · 7.5 CVSS v3.1 Published 2021-07-21
Fix available
A fix is available. Upgrade to 4.2.17-1 / 6.4.9-5 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges 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
Collabora Online is a collaborative online office suite. In versions prior to 4.2.17-1 and version 6.4.9-5, unauthenticated attackers are able to gain access to files which are currently opened by other users in the Collabora Online editor. For successful exploitation the attacker is required to guess the file identifier - the predictability of this file identifier is dependent on external file-storage implementations (this is a potential "IDOR" - Insecure Direct Object Reference - vulnerability). Versions 4.2.17-1 and 6.4.9-5 contain patches for this issue. There is no known workaround except updating the Collabora Online application to one of the patched releases.

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 confidence

Collabora Online versions prior to 4.2.17-1 and 6.4.9-5 contain an IDOR vulnerability allowing unauthenticated attackers to access files currently opened by other users by guessing the file identifier. The exploitability depends on the predictability of file identifiers, which varies by storage implementation.

MitigationUpdate Collabora Online to version 4.2.17-1 or 6.4.9-5 or later. No workaround is available; the only remediation is applying the patched release.

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
OnlineApplication
Affected:< 4.2.17-1>= 6.4.0, < 6.4.9-5

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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. Check installed Collabora Online version
    Run package manager query (e.g., dpkg -l collabora* or rpm -q collabora*) or access the Collabora Online about page via the UI at /about
    Affected if Version is below 4.2.17-1 OR version is 6.4.0 through 6.4.9-4
  2. Identify storage backend in use
    Examine the WOPI host configuration (typically in /etc/loolwsd/loolwsd.xml or equivalent) for the storage backend setting (e.g., wopi, webdav, or other)
    Affected if Storage backend produces predictable or enumerable file identifiers (specific predictability depends on backend implementation)
  3. Verify WOPI host integration
    Confirm that Collabora Online is integrated with a WOPI host for document editing, as this is the attack vector for the IDOR
    Affected if WOPI host integration is active and accessible to unauthenticated users

User is affected if Collabora Online version falls within the vulnerable ranges AND the storage backend produces predictable file identifiers that can be guessed by unauthenticated attackers.

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
Upgrade available Upgrade to 4.2.17-1 / 6.4.9-5 or later
Fixed in 4.2.17-16.4.9-5
Interim mitigation

Update Collabora Online to version 4.2.17-1 or 6.4.9-5 or later. No workaround is available; the only remediation is applying the patched release.

Fix this in Online Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2021-32744 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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