ServerApplication · Onlyoffice

CVE-2021-43445

CRITICAL · 9.8 CVSS v3.1 Published 2023-01-23
Fix available
A fix is available. Upgrade to after 7.0.0.49 or later.
See remediation →
100/100
Remediation priority · Urgent
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
ONLYOFFICE all versions as of 2021-11-08 is affected by Incorrect Access Control. An attacker can authenticate with the web socket service of the ONLYOFFICE document editor which is protected by JWT auth by using a default JWT signing key.

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

ONLYOFFICE Document Server uses JWT authentication to protect its web socket service. The vulnerability allows an attacker to bypass this authentication mechanism by using a known default JWT signing key that ships with the software. This enables unauthorized access to the document editing web socket service.

MitigationChange the default JWT signing key to a unique, strong secret in the ONLYOFFICE configuration and ensure it is not exposed or guessable.

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
ServerApplication
Affected:<= 7.0.0.49

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
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 checks

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

  1. Check installed Onlyoffice Server version
    Determine the installed version of Onlyoffice Document Server using system commands, package manager, or the built-in about page
    Affected if Version is 7.0.0.49 or lower
  2. Locate JWT configuration
    Find the JWT configuration file in the Onlyoffice documentserver configuration directory (typically /etc/onlyoffice/documentserver/)
    Affected if JWT configuration file exists and contains secret/key settings
  3. Inspect JWT signing key
    Open the JWT configuration file and examine the jwt.secret or similar key parameter value
    Affected if The configured JWT signing key matches the default key that ships with the software (the well-known default value) rather than a unique custom secret
  4. Verify web socket service exposure
    Confirm the web socket service (ws/wss on the configured port) is accessible and inspect whether JWT validation is enforced
    Affected if The web socket endpoint responds and accepts connections using the default JWT signing key

Environment is affected if running Onlyoffice Server version 7.0.0.49 or lower AND the default JWT signing key is still in use in the configuration.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 7.0.0.49
Interim mitigation

Change the default JWT signing key to a unique, strong secret in the ONLYOFFICE configuration and ensure it is not exposed or guessable.

Recommended fix Moderate confidence

7.1.0 or later

  1. 1. Upgrade ONLYOFFICE Server to version 7.1.0 or later (a version beyond the vulnerable 7.0.0.49 release).
  2. 2. After upgrading, locate the JWT secret configuration in the ONLYOFFICE Server settings (typically in the configuration files or web panel).
  3. 3. Change the default JWT signing key to a strong, unique secret value that is not publicly known or guessable.
  4. 4. Restart the ONLYOFFICE services to apply the new configuration.
  5. 5. Verify that the JWT authentication is working correctly with the new key.
Caveat Ensure any existing integrations or clients are updated with the new JWT secret before restarting services, or they will fail to authenticate.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
Get the upgrade done

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Scan for this in your stack

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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-2021-43445 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
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