CVE-2021-39349Public exploitNetwork attack vector

Authenticated stored XSS via unsanitized admin parameters

Published Oct 15, 2021 · Updated Feb 14, 2025

Stored XSS in Author Bio Box 3.3.1 and earlier allows remote authenticated users to execute scripts via crafted administrator parameters. The plugin stores several administrator-controlled values from includes/admin/class-author-bio-box-admin.php without sufficient validation or sanitization, allowing injected web script to execute when rendered. Administrative access is required, and the documented impact is script execution with limited confidentiality and integrity effects rather than service interruption.

CVSS severity4.8
Medium
EPSS probability1.14%
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 Author Bio Box 3.3.1 and earlier allows remote authenticated users to execute scripts via crafted administrator parameters. The plugin stores several administrator-controlled values from includes/admin/class-author-bio-box-admin.php without sufficient validation or sanitization, allowing injected web script to execute when rendered. Administrative access is required, and the documented impact is script execution with limited confidentiality and integrity effects rather than service interruption.

The record

CVE
CVE-2021-39349
Published
Oct 15, 2021
Updated
Feb 14, 2025
Vendor
Claudio Sanches
Product
Author Bio Box
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Oct 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Feb 14, 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?

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

  1. Affected versionversion=3.3.1 <=3.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Claudio Sanches · Author Bio Boxversion=3.3.1 <=3.3.1

Published CVSS scores

5.5Wordfence CNACVSS:3.1/AV:N/AC:L/PR:H/UI:N/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
2.1NIST NVDAV:N/AC:H/Au:S/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

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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