CVE-2023-4321Public exploitNetwork attack vector

Stored script execution via uploaded XHTML assets

Published Aug 14, 2023 · Updated Oct 3, 2024

Stored XSS in Cockpit CMS before 2.4.3 allows remote authenticated users to execute script through an uploaded XHTML asset. The Assets module upload filter omits the xhtml extension and application/xhtml+xml MIME type, so attacker-controlled active markup is stored and served. Assets-manager access is required, and opening the stored asset executes its script in the visitor's browser under the Cockpit origin.

CVSS severity8.3
High
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Cockpit CMS before 2.4.3 allows remote authenticated users to execute script through an uploaded XHTML asset. The Assets module upload filter omits the xhtml extension and application/xhtml+xml MIME type, so attacker-controlled active markup is stored and served. Assets-manager access is required, and opening the stored asset executes its script in the visitor's browser under the Cockpit origin.

The record

CVE
CVE-2023-4321
Published
Aug 14, 2023
Updated
Oct 3, 2024
Vendor
Cockpit HQ
Product
Cockpit CMS
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.4.3
  2. Affected versionversion=unspecified <2.4.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Cockpit HQ · Cockpit CMSversion=0 <2.4.3; version=unspecified <2.4.3

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
8.3huntr.devCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

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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