CVE-2021-34111Public exploitNetwork attack vector

Root command execution via batch username injection

Published May 20, 2022 · Updated Aug 4, 2024

Command injection in Thecus N4800Eco allows remote authenticated users to execute operating-system commands with root privileges. The batch user-creation path in /adm/setmain.php stores shell substitution syntax in a username; deleting that user evaluates the stored text as a shell command. Access to the web control panel is required, and the command output becomes visible in the appliance system log.

CVSS severity9.8
Critical
EPSS probability2.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Thecus N4800Eco allows remote authenticated users to execute operating-system commands with root privileges. The batch user-creation path in /adm/setmain.php stores shell substitution syntax in a username; deleting that user evaluates the stored text as a shell command. Access to the web control panel is required, and the command output becomes visible in the appliance system log.

The record

CVE
CVE-2021-34111
Published
May 20, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-78, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 2022CVE 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Command and Scripting Interpreter: Unix Shell

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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