CVE-2024-3155 in Post Grid, Form Maker, Popup Maker, WooCommerce Blocks, Post Blocks, Post Carousel Plugin
Summary
by MITRE • 05/21/2024
The Post Grid, Form Maker, Popup Maker, WooCommerce Blocks, Post Blocks, Post Carousel – Combo Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via several parameters in all versions up to, and including, 2.2.80 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 05/11/2026
This vulnerability affects the Post Grid, Form Maker, Popup Maker, WooCommerce Blocks, Post Blocks, and Post Carousel – Combo Blocks plugin for WordPress, specifically impacting all versions up to and including 2.2.80. The issue stems from inadequate input sanitization and output escaping mechanisms within the plugin's codebase, creating a stored cross-site scripting vulnerability that can be exploited by authenticated attackers. The vulnerability is particularly concerning because it requires only contributor-level access or higher, making it accessible to users who have been granted relatively modest permissions within a WordPress installation.
The technical flaw manifests through several parameters within the plugin's functionality where user input is not properly sanitized before being stored in the database and subsequently displayed on web pages. When an authenticated attacker with contributor privileges or higher submits malicious input through these vulnerable parameters, the malicious code gets stored persistently within the WordPress database. This stored content then executes whenever any user, including administrators, accesses pages containing the injected script, creating a classic stored XSS attack vector. The vulnerability operates at the application layer, where the plugin fails to properly escape output before rendering content to users, allowing malicious scripts to be executed in the context of the victim's browser.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities including session hijacking, credential theft, data exfiltration, and privilege escalation within the WordPress environment. An attacker could potentially inject scripts that redirect users to malicious sites, steal cookies and session tokens, or even modify content on the target website. Given that contributors typically have the ability to create and edit posts, pages, and media, this vulnerability provides attackers with a persistent means of maintaining access to compromised sites. The attack can be particularly insidious because the malicious code executes automatically whenever users access affected pages, making detection more difficult and potentially allowing for long-term persistence.
Mitigation strategies should focus on immediate patching of the affected plugin versions, as well as implementing additional security measures such as input validation and output escaping at the application level. Organizations should also consider implementing web application firewalls to help detect and prevent exploitation attempts, along with regular security audits of WordPress plugins and themes to identify similar vulnerabilities. The vulnerability aligns with CWE-79, which describes cross-site scripting flaws where untrusted data is directly output to web pages without proper sanitization or escaping, and follows ATT&CK technique T1059.001 for command and scripting interpreter, as attackers can leverage the XSS vulnerability to execute malicious scripts. Regular updates and security monitoring are essential to prevent exploitation of this class of vulnerability, as the stored nature of the attack means that once an attacker successfully injects malicious code, it can persist and affect multiple users over time without requiring repeated exploitation attempts.