CVE-2021-4304Network attack vector

Authenticated command execution via unchecked toolbox verb

Published Jan 5, 2023 · Updated May 28, 2025

Command injection in EPrints User Group ulcc-core before 2021-02-05 allows remote authenticated users to execute server commands. The cgi/toolbox/toolbox handler passes the cmd parameter to Perl eval without restricting the requested toolbox function; the password is used only to validate the login. A valid repository account and network access to the toolbox CGI endpoint are required, and successful exploitation runs code with the web application's privileges.

CVSS severity9.8
Critical
EPSS probability2.15%
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 EPrints User Group ulcc-core before 2021-02-05 allows remote authenticated users to execute server commands. The cgi/toolbox/toolbox handler passes the cmd parameter to Perl eval without restricting the requested toolbox function; the password is used only to validate the login. A valid repository account and network access to the toolbox CGI endpoint are required, and successful exploitation runs code with the web application's privileges.

The record

CVE
CVE-2021-4304
Published
Jan 5, 2023
Updated
May 28, 2025
Vendor
EPrints User Group
Product
ulcc-core
Classifications
CWE-77, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 5, 2023CVE publishedPublication date reported by the CVE source.
  2. May 28, 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?

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  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

EPrints User Group · ulcc-coreversion=n/a

Published CVSS scores

6.5VulDBAV:N/AC:L/Au:S/C:P/I:P/A:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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.

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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