CVE-2021-24350Public exploitNetwork attack vector

Administrator-session script execution via unencoded User-Agent rendering

Published Jun 14, 2021 · Updated Aug 3, 2024

Stored XSS in the Visitors WordPress plugin through 0.3 allows remote attackers to execute script via a crafted HTTP User-Agent. The plugin stores the attacker-controlled header and renders it on the WordPress admin visitors page without validation or output encoding. Exploitation requires an administrator to open that page, after which the script runs within the administrator's WordPress session.

CVSS severity6.1
Medium
EPSS probability1.30%
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 the Visitors WordPress plugin through 0.3 allows remote attackers to execute script via a crafted HTTP User-Agent. The plugin stores the attacker-controlled header and renders it on the WordPress admin visitors page without validation or output encoding. Exploitation requires an administrator to open that page, after which the script runs within the administrator's WordPress session.

The record

CVE
CVE-2021-24350
Published
Jun 14, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 14, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1190Exploit Public-Facing Application

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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