CVE-2021-24180Public exploitNetwork attack vector

Authenticated reflected XSS via unencoded lang parameter

Published Apr 5, 2021 · Updated Aug 3, 2024

Reflected XSS in Barry Kooij Related Posts for WordPress before 2.0.4 allows remote authenticated users to run script via a malicious URL. In classes/meta-boxes/class-meta-box-manage.php, the edit-post view appends the lang GET value to an anchor href without validation or output encoding. A user who can edit posts must follow the crafted link, after which the injected script executes in that user's browser.

CVSS severity5.4
Medium
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Barry Kooij Related Posts for WordPress before 2.0.4 allows remote authenticated users to run script via a malicious URL. In classes/meta-boxes/class-meta-box-manage.php, the edit-post view appends the lang GET value to an anchor href without validation or output encoding. A user who can edit posts must follow the crafted link, after which the injected script executes in that user's browser.

The record

CVE
CVE-2021-24180
Published
Apr 5, 2021
Updated
Aug 3, 2024
Vendor
Barry Kooij
Product
Related Posts for WordPress
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 5, 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?

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

  1. Affected versionversion=2.0.4 <2.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Barry Kooij · Related Posts for WordPressversion=2.0.4 <2.0.4

Published CVSS scores

3.5NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/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')
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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