CVE-2024-3866: ninja forms XSS — Fix

Description

The Ninja Forms Contact Form plugin for WordPress is vulnerable to Reflected Self-Based Cross-Site Scripting via the 'Referer' header in all versions up to, and including, 3.8.15 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Successful exploitation of this vulnerability requires "maintenance mode" for a targeted form to be enabled. However, there is no setting available to the attacker or even an administrator-level user to enable this mode. The mode is only enabled during a required update, which is a very short window of time. Additionally, because of the self-based nature of this vulnerability, attackers would have to rely on additional techniques to execute a supplied payload in the context of targeted user.

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CVSS v3.1 Score

4.7

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
ninjaforms	ninja_forms	< 3.8.16

References

Advisories & Patches

https://plugins.trac.wordpress.org/changeset/3153292/ninja-forms

Other References

https://www.wordfence.com/threat-intel/vulnerabilities/id/f6d6b82d-574d-4a56-9aef-42343c4b7c43?source=cve

Frequently Asked Questions

What is CVE-2024-3866? +

The Ninja Forms Contact Form plugin for WordPress is vulnerable to Reflected Self-Based Cross-Site Scripting via the 'Referer' header in all versions up to, and including, 3.8.15 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Successful exploitation of this vulnerability requires "maintenance mode" for a targeted form to be enabled. However, there is no setting available to the attacker or even an administrator-level user to enable this mode. The mode is only enabled during a required update, which is a very short window of time. Additionally, because of the self-based nature of this vulnerability, attackers would have to rely on additional techniques to execute a supplied payload in the context of targeted user. It has a CVSS v3.1 base score of 4.7 (MEDIUM).

How severe is CVE-2024-3866? +

CVE-2024-3866 has a CVSS v3.1 score of 4.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-3866? +

CVE-2024-3866 affects products from ninjaforms, specifically: ninja_forms. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-3866? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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