CVE-2025-28975: Alike WordPress Plugin XSS Vulnerability

CVE-2025-28975 Overview

CVE-2025-28975 is a Reflected Cross-Site Scripting (XSS) vulnerability affecting the Alike - WordPress Custom Post Comparison plugin developed by redqteam. The vulnerability stems from improper neutralization of user-supplied input during web page generation, allowing attackers to inject malicious scripts that execute in the context of a victim's browser session.

Critical Impact

Attackers can exploit this reflected XSS vulnerability to execute arbitrary JavaScript in the browsers of WordPress site visitors, potentially leading to session hijacking, credential theft, or further attacks against authenticated users.

Affected Products

• Alike - WordPress Custom Post Comparison plugin versions up to and including 3.0.1
• WordPress installations running vulnerable versions of the Alike plugin

Discovery Timeline

• 2025-08-14 - CVE-2025-28975 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-28975

Vulnerability Analysis

This vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation). The Alike plugin fails to properly sanitize user-controlled input before reflecting it back in the HTML response, enabling reflected XSS attacks that require user interaction to trigger.

The attack requires a network vector where an attacker crafts a malicious URL containing JavaScript payloads. When a victim clicks the crafted link, the malicious script executes within their browser session with the same privileges as the legitimate WordPress site, potentially affecting the confidentiality, integrity, and availability of user data.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and output encoding within the Alike plugin's code. When processing user input for the post comparison functionality, the plugin fails to properly escape special characters that could be interpreted as HTML or JavaScript, allowing attackers to inject executable code into the page response.

Attack Vector

The attack is executed over the network and requires user interaction—specifically, the victim must click a maliciously crafted link or visit a page containing the payload. The vulnerability has a changed scope, meaning the impact can extend beyond the vulnerable component to affect other resources within the user's browser context.

Exploitation typically involves an attacker crafting a URL containing XSS payload parameters and distributing this link through phishing emails, social engineering, or placing it on websites frequented by potential victims. When clicked, the malicious script executes with the victim's session context.

Detection Methods for CVE-2025-28975

Indicators of Compromise

• Unusual URL parameters containing encoded JavaScript or HTML tags in requests to WordPress sites using the Alike plugin
• Suspicious outbound connections from user browsers after visiting comparison pages
• Reports of unexpected browser behavior or pop-ups when using the Alike plugin functionality

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect common XSS patterns in URL parameters targeting WordPress plugins
• Monitor server access logs for requests containing suspicious encoded characters or JavaScript keywords in query strings
• Deploy browser-based security monitoring to detect unexpected script execution on WordPress sites

Monitoring Recommendations

• Enable verbose logging for the WordPress Alike plugin to capture all user input and identify potential attack attempts
• Configure intrusion detection systems to alert on XSS payload patterns in HTTP requests
• Regularly review WordPress access logs for anomalous requests targeting plugin endpoints

How to Mitigate CVE-2025-28975

Immediate Actions Required

• Update the Alike - WordPress Custom Post Comparison plugin to a version newer than 3.0.1 when a patched version becomes available
• Review WordPress site logs for any evidence of exploitation attempts
• Consider temporarily disabling the Alike plugin until a security patch is released
• Implement Content Security Policy (CSP) headers to mitigate the impact of potential XSS attacks

Patch Information

A security patch addressing this vulnerability should be obtained from the plugin developer. Monitor the Patchstack WordPress Vulnerability Advisory for updates on remediation guidance and patched versions.

WordPress administrators should regularly check for plugin updates through the WordPress admin dashboard and apply security updates as soon as they become available.

Workarounds

• Implement a Web Application Firewall (WAF) with XSS filtering capabilities to block malicious requests before they reach the vulnerable plugin
• Add Content Security Policy (CSP) headers to prevent inline script execution, limiting the impact of successful XSS attacks
• Restrict access to the plugin's comparison functionality to authenticated users only if business requirements permit
• Consider using WordPress security plugins that provide additional input sanitization layers

# Example: Add CSP headers to WordPress .htaccess
# Add to .htaccess in WordPress root directory
<IfModule mod_headers.c>
    Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';"
    Header set X-XSS-Protection "1; mode=block"
    Header set X-Content-Type-Options "nosniff"
</IfModule>