CVE-2021-28924Public exploitNetwork attack vector

Authenticated browser script execution via query-page markup injection

Published Apr 8, 2021 · Updated Aug 3, 2024

Cross-site scripting in Nagios Network Analyzer 2.4.2 allows remote authenticated users to execute script in their own browser. The Source Queries endpoint at /nagiosna/groups/queries/1 renders submitted content as executable HTML instead of neutralizing markup, as demonstrated with an image onerror handler. Exploitation requires an authenticated user to place attacker-supplied content into that user's session, exposing data and actions available to script in the application's origin.

CVSS severity6.1
Medium
EPSS probability10.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Nagios Network Analyzer 2.4.2 allows remote authenticated users to execute script in their own browser. The Source Queries endpoint at /nagiosna/groups/queries/1 renders submitted content as executable HTML instead of neutralizing markup, as demonstrated with an image onerror handler. Exploitation requires an authenticated user to place attacker-supplied content into that user's session, exposing data and actions available to script in the application's origin.

The record

CVE
CVE-2021-28924
Published
Apr 8, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1204.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 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?

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

4.3National Vulnerability DatabaseAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/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 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')
T1204.004User Execution: Malicious Copy and Paste

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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