Vulnerabilities

Flaws in Popup Builder Plugin Impacted Over 100,000 WordPress Sites

More than 100,000 WordPress websites were potentially affected by a series of vulnerabilities recently discovered and addressed in the Popup Builder plugin.

Ionut Arghire

March 13, 2020

More than 100,000 WordPress websites were potentially affected by a series of vulnerabilities recently discovered and addressed in the Popup Builder plugin.

Designed to help with the creation and management of promotional modal pop-ups for WordPress blogs and websites, Popup Builder also includes the ability to run custom JavaScript code when the pop-up is loaded.

Security researchers at WordPress security firm Defiant report that Popup Builder before version 3.64.1 is impacted by vulnerabilities that could allow attackers to inject malicious code without authentication, or leak user information and system configuration data.

The most important of the vulnerabilities is a high-severity stored cross-site scripting (XSS) bug tracked as CVE-2020-10196 and featuring a CVSS score of 8.3.

The security flaw could be exploited by an unauthenticated attacker to inject malicious JavaScript code into any pop-up, thus having it executed when the pop-up is loaded.

The plugin registered an AJAX hook intended to allow auto-saving of draft pop-ups, but the hook was found to be exposed to unprivileged users. Moreover, the function called by the hook did not include nonce checks or capability checks.

Because of that, an attacker could send a POST request to wp-admin/admin-ajax.php with a malicious JavaScript payload, which would result in the payload being saved to the pop-up’s settings and executed whenever the pop-up is displayed on a page.

While such vulnerabilities are typically abused to redirect users to malvertising sites or for information theft, the issue could also be leveraged for site takeover if the infected pop-up was displayed to a logged-in administrator, Defiant says.

Another issue addressed in the plugin this week is CVE-2020-10195 (CVSS score 6.3), which could allow a low-privileged authenticated user to export a list of all newsletter subscribers and system configuration details, or even grant themselves access to features of the plugin.

The vulnerabilities were reported to the plugin’s developer on March 5, with a fully patched version of Popup Builder (version 3.64.1) released on March 11.

“While we have not detected any malicious activity targeting Popup Builder, the stored XSS vulnerability can have a serious impact on site visitors and potentially even allow site takeover,” Defiant underlines.

Written By Ionut Arghire

Ionut Arghire is an international correspondent for SecurityWeek.

Latest News

Click to comment

Mapping Threat Intelligence to the NIST Compliance Framework Part 2

How threat intelligence is critical when justifying budget for GRC personnel, and for threat intelligence, incident response, security operations and CISO buyers.

Landon Winkelvoss

Password Dependency: How to Break the Cycle

Hackers rarely hack in anymore. They log in using stolen, weak, default, or otherwise compromised credentials. That’s why it’s so critical to break the password dependency cycle. But how can this be done?

Torsten George

Why CISOs Make Great Board Members

Cybersecurity-related risk is a top concern, so boards need to know they have the proper oversight in place. Even as first-timers, successful CISOs make for successful board members.

Galina Antova

A Change in Mindset: From a Threat-based to Risk-based Approach to Security

A threat-based approach to security often focuses on a checklist to meet industry requirements but overlooked the key component of security: reducing risk.

Marie Hattar