CVE-2021-43447Network attack vector

Unauthenticated document editing via WebSocket access

Published Jan 23, 2023 · Updated Apr 2, 2025

Authentication bypass in the ONLYOFFICE document editor as of 2021-11-08 allows remote attackers to edit documents without authentication. The document-editing WebSocket accepts unauthenticated connections and processes document changes without enforcing a valid editing session. Network access to the WebSocket is the only published gate, and the recorded impact is unauthorized modification rather than disclosure or interruption.

CVSS severity7.5
High
EPSS probability1.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in the ONLYOFFICE document editor as of 2021-11-08 allows remote attackers to edit documents without authentication. The document-editing WebSocket accepts unauthenticated connections and processes document changes without enforcing a valid editing session. Network access to the WebSocket is the only published gate, and the recorded impact is unauthorized modification rather than disclosure or interruption.

The record

CVE
CVE-2021-43447
Published
Jan 23, 2023
Updated
Apr 2, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-306, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
7.8NVDAV:N/AC:L/Au:N/C:N/I:C/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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