CVE-2025-22539: Custom Database Tables XSS Vulnerability

CVE-2025-22539 Overview

A Reflected Cross-Site Scripting (XSS) vulnerability has been identified in the WordPress Custom DataBase Tables plugin developed by ka2. This vulnerability arises from improper neutralization of input during web page generation, allowing attackers to inject malicious scripts that execute in the context of a victim's browser session.

The Custom DataBase Tables plugin enables WordPress administrators to create and manage custom database tables within their WordPress installations. Due to insufficient input sanitization, user-supplied input is reflected back to users without proper encoding, creating an attack vector for XSS exploitation.

Critical Impact

Attackers can craft malicious URLs that, when clicked by authenticated WordPress users, execute arbitrary JavaScript in the victim's browser. This can lead to session hijacking, credential theft, administrative account compromise, and further site manipulation.

Affected Products

• Custom DataBase Tables plugin versions up to and including 2.1.34
• WordPress installations running vulnerable versions of the custom-database-tables plugin
• Any website utilizing the affected plugin for custom database management

Discovery Timeline

• 2025-01-09 - CVE-2025-22539 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-22539

Vulnerability Analysis

This vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting. The Reflected XSS variant occurs when user input is immediately returned by the web application in an error message, search result, or other response that includes some or all of the input provided by the user as part of the request.

In the context of the Custom DataBase Tables plugin, the vulnerability allows malicious scripts to be injected through URL parameters or form inputs that are not properly sanitized before being rendered in the browser. When a victim clicks a crafted link or submits a manipulated form, the injected script executes with the privileges of the victim's session.

Root Cause

The root cause of this vulnerability is the failure to properly sanitize, validate, or encode user-supplied input before including it in dynamically generated web pages. The Custom DataBase Tables plugin does not adequately filter special characters such as <, >, ", and ' that are essential for constructing HTML and JavaScript code. This oversight allows attackers to break out of the intended data context and inject executable scripts.

Attack Vector

The attack vector for this Reflected XSS vulnerability involves crafting a malicious URL containing JavaScript payload and convincing an authenticated WordPress administrator or user to click the link. The attack flow typically proceeds as follows:

1. The attacker identifies a vulnerable parameter in the Custom DataBase Tables plugin interface
2. The attacker crafts a URL embedding malicious JavaScript in the vulnerable parameter
3. The attacker distributes the malicious link via phishing emails, social media, or other channels
4. When a victim clicks the link while authenticated to WordPress, the malicious script executes
5. The script can steal session cookies, perform actions as the victim, or redirect to malicious sites

The vulnerability mechanism involves user-controlled input being reflected in the page output without proper HTML entity encoding. When rendering plugin pages, unsanitized parameter values are embedded directly into the HTML response, allowing script tags and JavaScript event handlers to execute in the victim's browser context.

Detection Methods for CVE-2025-22539

Indicators of Compromise

• Unusual URL parameters containing encoded JavaScript code or HTML tags in requests to WordPress admin pages
• Access logs showing requests with suspicious payloads containing <script>, javascript:, or event handlers like onerror=
• Reports of unexpected browser behavior or unauthorized actions when accessing Custom DataBase Tables plugin pages
• Session anomalies indicating potential cookie theft or session hijacking

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common XSS patterns in URL parameters and POST data
• Monitor server access logs for requests containing typical XSS payloads such as <script>, alert(), or HTML event attributes
• Deploy browser-based security controls and Content Security Policy (CSP) headers to mitigate script execution
• Use automated vulnerability scanners to identify unpatched WordPress plugins

Monitoring Recommendations

• Enable detailed logging for WordPress admin area access and plugin interactions
• Configure alerts for unusual patterns in HTTP requests targeting the Custom DataBase Tables plugin endpoints
• Regularly audit WordPress plugin versions and compare against known vulnerable versions
• Implement real-time monitoring for JavaScript injection attempts in request parameters

How to Mitigate CVE-2025-22539

Immediate Actions Required

• Update the Custom DataBase Tables plugin to a version newer than 2.1.34 when a patched version becomes available
• Review and remove the plugin if it is not essential to site operations until a patch is released
• Implement Content Security Policy (CSP) headers to restrict inline script execution
• Train users to recognize and avoid clicking suspicious links, especially those with unusual URL parameters

Patch Information

Refer to the Patchstack WordPress Vulnerability Report for the latest patch information and remediation guidance. Monitor the WordPress plugin repository for updated versions of Custom DataBase Tables that address this vulnerability.

Workarounds

• Implement a Web Application Firewall (WAF) with XSS filtering rules to block malicious payloads
• Restrict access to the WordPress admin area to trusted IP addresses only
• Add Content Security Policy headers to prevent execution of inline scripts and unauthorized script sources
• Disable or remove the Custom DataBase Tables plugin until an official patch is available if the plugin is not critical to operations

# Example: Adding Content Security Policy header in Apache .htaccess
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';"

# Example: Adding CSP header in Nginx configuration
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';";