CVE-2021-34816Public exploitNetwork attack vector

Authenticated code execution via unvalidated plugin source

Published Jul 21, 2021 · Updated Aug 4, 2024

Argument injection in Etherpad 1.8.13 allows remote authenticated users with administrator access to execute code through plugin installation. The backend passes the WebSocket-supplied plugin name directly to npm install without validation, accepting attacker-controlled package URLs and post-install scripts. An administrator account must exist and be compromised or controlled; successful exploitation runs commands with the Etherpad server process's privileges.

CVSS severity7.2
High
EPSS probability2.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Argument injection in Etherpad 1.8.13 allows remote authenticated users with administrator access to execute code through plugin installation. The backend passes the WebSocket-supplied plugin name directly to npm install without validation, accepting attacker-controlled package URLs and post-install scripts. An administrator account must exist and be compromised or controlled; successful exploitation runs commands with the Etherpad server process's privileges.

The record

CVE
CVE-2021-34816
Published
Jul 21, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-88, T1059
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
T1059Command and Scripting Interpreter

Public exploit references

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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