CVE-2021-40369Network attack vector

XSS via unescaped Denounce URL

Published Nov 24, 2021 · Updated Aug 4, 2024

Cross-site scripting in Apache JSPWiki up to 2.11.0.M8 allows remote attackers to execute JavaScript in a victim browser via a crafted Denounce plugin link. The Denounce plugin renders attacker-supplied URLs without adequate neutralization, allowing script injection into generated wiki content. Victim browser interaction with the crafted link is required; the demonstrated consequence is script execution and sensitive information disclosure, not server compromise.

CVSS severity6.1
Medium
EPSS probability3.31%
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 Apache JSPWiki up to 2.11.0.M8 allows remote attackers to execute JavaScript in a victim browser via a crafted Denounce plugin link. The Denounce plugin renders attacker-supplied URLs without adequate neutralization, allowing script injection into generated wiki content. Victim browser interaction with the crafted link is required; the demonstrated consequence is script execution and sensitive information disclosure, not server compromise.

The record

CVE
CVE-2021-40369
Published
Nov 24, 2021
Updated
Aug 4, 2024
Vendor
The Apache Software Foundation
Product
Apache JSPWiki
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 24, 2021CVE 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?

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

  1. Affected versionversion=Apache JSPWiki <=2.11.0.M8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache JSPWikiversion=Apache JSPWiki <=2.11.0.M8

Published CVSS scores

5.0NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1NVDCVSS: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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

No public exploit references are available in this record.

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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