CVE-2021-25056

Ninja Forms Contact Form <= 3.6.9 - Cross-Site Scripting via field label

2022-06-13 00:00
Muhammad Adel

Strategic Overview

Status
Patched in 3.6.10
Affected Plugin
Ninja Forms – The Contact Form Builder That Grows With You
Affected Version
<= 3.6.9
CVSS
4.8Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-25056
View all Ninja Forms – The Contact Form Builder That Grows With You vulnerabilities

At a glance

CVE-2021-25056 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Ninja Forms WordPress plugin, affecting versions <= 3.6.9. It carries a CVSS score of 4.8 (reachable over the network; low attack complexity). The issue is fixed in version 3.6.10; sites on affected versions should update now. Disclosed June 2022, reported by Muhammad Adel.

Vulnerability Overview

The Ninja Forms Contact Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via field labels in versions up to, and including, 3.6.9 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers with administrative level permissions and above to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Ninja Forms <= 3.6.9 takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Ninja Forms the fix is 3.6.10: builds <= 3.6.9 are affected, anything from 3.6.10 onward is not.

Remediation

Update to version 3.6.10, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Ninja Forms: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Ninja Forms 3.6.10 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-25056https://www.wordfence.com/threat-intel/vulnerabilities/id/eaf0d324-bf2c-4da7-b2ab-f53f7b7881f2https://nvd.nist.gov/vuln/detail/CVE-2021-25056

Related records

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