CVE-2021-43584Public exploitNetwork attack vector

Administrative session compromise via unsafe jQuery HTML insertion

Published Jan 24, 2024 · Updated Jun 16, 2025

DOM-based XSS in Nagios NCPA before 2.4.0 allows attackers to execute JavaScript through the Tail Event Logs name filter. The tail.html click handler passes the untrusted name value to jQuery .html(), which parses it as markup instead of rendering text. An administrative user must enter the payload; code then runs in that user's browser session and can expose the NCPA community string.

CVSS severity4.8
Medium
EPSS probability1.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DOM-based XSS in Nagios NCPA before 2.4.0 allows attackers to execute JavaScript through the Tail Event Logs name filter. The tail.html click handler passes the untrusted name value to jQuery .html(), which parses it as markup instead of rendering text. An administrative user must enter the payload; code then runs in that user's browser session and can expose the NCPA community string.

The record

CVE
CVE-2021-43584
Published
Jan 24, 2024
Updated
Jun 16, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jan 24, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 16, 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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