The U.S. federal government National Vulnerability Database released an advisory about a Stored Cross-Site Scripting vulnerability in the popular Popup Maker plugin for WordPress.
Popup Maker for WordPress
A vulnerability was discovered in the “Popup Maker– Popup for opt-ins, lead gen, & more” WordPress plugin which is installed in over 700,000 sites.
The Popup Maker plugin incorporates with a number of the most popular contact types with functions created to drive conversions in WooCommerce shops, e-mail newsletter signups and other popular applications associated to lead generation.
Although the plugin has only been around since 2021 it has experienced phenomenal growth and made over 4,000 five-star reviews.
Popup Maker Vulnerability
The vulnerability impacting this plugin is called saved cross-site scripting (XSS). It’s called “stored” due to the fact that a destructive script is submitted to the site and kept on the server itself.
XSS vulnerabilities usually happen when an input fails to sanitize what is being submitted. Anywhere that a user can input information is can become vulnerable there is an absence of control over what can be uploaded.
This particular vulnerability can happen when a hacker can gain the qualifications of a user with at least a contributor level of gain access to initiates the attack.
The U.S. Government National Vulnerability Database explains the factor for the vulnerability and how an attack can happen:
“The Popup Maker WordPress plugin before 1.16.9 does not verify and get away among its shortcode attributes, which could permit users with a function as low as factor to perform Stored Cross-Site Scripting attacks.”
The Popup Maker Plugin changelog for version V1.16.9 notes:
Security company WPScan (owned by Automattic) released a proof of concept that demonstrates how the exploit works.
“As a factor, put the following shortcode in a post/page
The XSS will be set off when previewing/viewing the post/page and sending the form”
While there is no description of how bad the make use of can be, in general, Stored XSS vulnerabilities can have serious effects including complete site takeover, user data exposure and the planting of Trojan horse programs.
There have been subsequent updates given that the original spot was provided for version 1.16.9, including a newer upgrade that repairs a bug that was presented with the security spot.
The most current version of the Popup Maker plugin is V1.17.1.
Publishers who have the plugin installed must think about upgrading the most recent version.
Read the U.S. Government National Vulnerability Database advisory:
Read the WPScan Advisory
Popup Maker < 1.16.9-- Factor+ Kept XSS via Subscription Type
Included image by Best SMM Panel/Asier Romero