CVE-2021-39353Network attack vector

Stored cross-site scripting via nonce-free form creation

Published Nov 19, 2021 · Updated Feb 14, 2025

Cross-site request forgery in Easy Registration Forms 2.1.1 and earlier allows remote attackers to inject stored scripts through form creation. The ajax_add_form function in includes/class-form.php processes a form-creation request without validating a WordPress nonce, allowing attacker-supplied script content to be stored. Exploitation requires a privileged site user's browser to submit attacker-controlled content; the stored script executes for later viewers.

CVSS severity8.8
High
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in Easy Registration Forms 2.1.1 and earlier allows remote attackers to inject stored scripts through form creation. The ajax_add_form function in includes/class-form.php processes a form-creation request without validating a WordPress nonce, allowing attacker-supplied script content to be stored. Exploitation requires a privileged site user's browser to submit attacker-controlled content; the stored script executes for later viewers.

The record

CVE
CVE-2021-39353
Published
Nov 19, 2021
Updated
Feb 14, 2025
Vendor
Easy Registration Forms
Product
Easy Registration Forms
Classifications
CWE-352, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 19, 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=2.1.1 <=2.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Easy Registration Forms · Easy Registration Formsversion=2.1.1 <=2.1.1

Published CVSS scores

8.8WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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-352Cross-Site Request Forgery (CSRF)
T1189Drive-by Compromise

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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