CVE-2025-22628: FolioVision Filled In XSS Vulnerability

CVE-2025-22628 Overview

CVE-2025-22628 is a Stored Cross-Site Scripting (XSS) vulnerability affecting the FolioVision Filled In WordPress plugin. The vulnerability stems from improper neutralization of input during web page generation (CWE-79), allowing attackers to inject malicious scripts that persist in the application and execute in the context of other users' browsers.

Critical Impact

Attackers can leverage this Stored XSS vulnerability to execute arbitrary JavaScript in victims' browsers, potentially leading to session hijacking, credential theft, and administrative account compromise on affected WordPress installations.

Affected Products

• FolioVision Filled In WordPress Plugin versions up to and including 1.9.2
• WordPress installations running vulnerable versions of the Filled In plugin

Discovery Timeline

• 2025-03-27 - CVE-2025-22628 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-22628

Vulnerability Analysis

This vulnerability is classified as a Stored XSS (also known as Persistent XSS), which is particularly dangerous because the malicious payload is permanently stored on the target server. Unlike Reflected XSS attacks that require victims to click malicious links, Stored XSS attacks execute automatically when users view the affected page content.

The vulnerability exists within the Filled In plugin's input handling mechanisms, where user-supplied data is not properly sanitized before being stored and subsequently rendered in web pages. This allows attackers to inject JavaScript code that will execute in the browser context of any user who views the affected content.

According to the Patchstack Vulnerability Report, this vulnerability can be chained with Cross-Site Request Forgery (CSRF), meaning an attacker could potentially trick an authenticated administrator into unknowingly submitting the malicious payload.

Root Cause

The root cause of CVE-2025-22628 is insufficient input validation and output encoding within the Filled In plugin. When processing form submissions or user input, the plugin fails to properly neutralize potentially dangerous HTML and JavaScript content before storing it in the database and rendering it back to users.

WordPress plugins that handle form data must implement proper sanitization using functions like wp_kses(), esc_html(), and esc_attr() to prevent XSS attacks. The absence or improper implementation of these security measures in the Filled In plugin allows malicious scripts to bypass security controls.

Attack Vector

The attack vector for this vulnerability involves submitting specially crafted input containing JavaScript code through the plugin's form handling functionality. The attack chain typically involves:

1. An attacker identifies input fields processed by the Filled In plugin that lack proper sanitization
2. Malicious JavaScript payloads are submitted through these fields
3. The payload is stored in the WordPress database without proper encoding
4. When administrators or users view pages containing this data, the malicious script executes in their browser context
5. The script can steal session cookies, perform actions on behalf of the victim, or redirect users to malicious sites

The CSRF component mentioned in the security advisory indicates that the initial payload injection may be possible without direct authentication, by tricking an authenticated user into submitting a malicious request.

Detection Methods for CVE-2025-22628

Indicators of Compromise

• Unexpected JavaScript code or HTML tags appearing in form submission data stored by the Filled In plugin
• Unusual user activity patterns such as unexplained administrative actions or account modifications
• Browser security warnings or Content Security Policy (CSP) violations in logs from pages containing Filled In plugin content
• Reports from users experiencing unexpected redirects or pop-ups when viewing WordPress pages

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common XSS patterns in form submissions
• Review server logs for suspicious POST requests containing script tags or JavaScript event handlers targeting Filled In plugin endpoints
• Deploy Content Security Policy headers and monitor violation reports for unauthorized script execution attempts
• Conduct regular security scans of WordPress installations using tools like WPScan to identify vulnerable plugin versions

Monitoring Recommendations

• Enable WordPress audit logging to track all form submissions and administrative changes
• Configure real-time alerts for database queries containing potentially malicious content patterns
• Monitor browser console errors and CSP violation reports from pages utilizing the Filled In plugin
• Implement file integrity monitoring for plugin files to detect unauthorized modifications

How to Mitigate CVE-2025-22628

Immediate Actions Required

• Update the Filled In plugin to a patched version immediately if one is available from FolioVision
• If no patch is available, consider temporarily deactivating the Filled In plugin until a security update is released
• Implement a Web Application Firewall (WAF) with XSS filtering rules to provide defense-in-depth protection
• Review and sanitize any existing data stored by the Filled In plugin for potentially malicious content

Patch Information

WordPress administrators should check the official WordPress plugin repository and FolioVision's website for security updates addressing CVE-2025-22628. The vulnerability affects all versions of Filled In through 1.9.2, so ensure you update to a version higher than 1.9.2 once released.

For the latest security advisory and patch information, refer to the Patchstack Vulnerability Report.

Workarounds

• Implement strict Content Security Policy (CSP) headers to mitigate the impact of XSS attacks by restricting script execution sources
• Use WordPress security plugins such as Wordfence or Sucuri that provide real-time XSS attack protection
• Restrict access to the WordPress admin area to trusted IP addresses to reduce the attack surface
• Consider replacing the Filled In plugin with an alternative form solution that has a stronger security track record

# Example Content Security Policy header configuration for Apache
# Add to .htaccess or virtual host configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'self';"