CVE-2021-24351

The Plus Addons for Elementor Page Builder <= 4.1.11 - Reflected Cross-Site Scripting

2021-05-31 00:00
Nicolas Verdier

Strategic Overview

Status
Patched in 4.1.12
Affected Plugin
The Plus Addons for Elementor Page Builder Pro
Affected Version
< 4.1.12
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24351
View all The Plus Addons for Elementor Page Builder Pro vulnerabilities

At a glance

CVE-2021-24351 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the The Plus Addons for Elementor Page Builder Pro WordPress plugin, affecting versions < 4.1.12. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.1.12; sites on affected versions should update now. Disclosed May 2021, reported by Nicolas Verdier.

Vulnerability Overview

The theplus_more_post AJAX action of The Plus Addons for Elementor Page Builder WordPress plugin before 4.1.12 did not properly sanitise some of its fields, leading to a reflected Cross-Site Scripting (exploitable on both unauthenticated and authenticated users)

Technical Analysis

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

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

Reaching this weakness in The Plus Addons for Elementor Page Builder Pro < 4.1.12 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 The Plus Addons for Elementor Page Builder Pro the fix is 4.1.12: builds < 4.1.12 are affected, anything from 4.1.12 onward is not.

Remediation

Update to version 4.1.12, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to The Plus Addons for Elementor Page Builder Pro: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: The Plus Addons for Elementor Page Builder Pro 4.1.12 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24351https://www.wordfence.com/threat-intel/vulnerabilities/id/caa09e12-60f9-4ef4-85f7-dadb6833e077https://nvd.nist.gov/vuln/detail/CVE-2021-24351

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C