CVE-2025-23739: WP Ultimate Reviews FREE XSS Vulnerability

CVE-2025-23739 Overview

A Reflected Cross-Site Scripting (XSS) vulnerability has been identified in the WP Ultimate Reviews FREE WordPress plugin developed by jtibbles. This vulnerability allows attackers to inject malicious scripts into web pages viewed by users, potentially leading to session hijacking, credential theft, or further attacks against site visitors.

Critical Impact

This XSS vulnerability enables attackers to execute arbitrary JavaScript in the context of a victim's browser session, potentially compromising user credentials, session tokens, and sensitive data processed by the affected WordPress sites.

Affected Products

• WP Ultimate Reviews FREE plugin versions up to and including 1.0.2
• WordPress installations utilizing the wp-ultimate-reviews-free plugin

Discovery Timeline

• 2025-03-03 - CVE-2025-23739 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-23739

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting. The WP Ultimate Reviews FREE plugin fails to properly sanitize user-supplied input before incorporating it into dynamically generated web pages. When a victim clicks on a crafted malicious link or visits an attacker-controlled page, the injected script executes within their browser session with the same privileges as the legitimate site.

Reflected XSS attacks require social engineering to trick users into clicking malicious links, but once executed, the attacker can perform any action the victim can perform on the affected WordPress site. This includes reading sensitive information displayed on the page, modifying page content, or redirecting users to phishing sites.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and output encoding within the WP Ultimate Reviews FREE plugin. User-controlled data is reflected back to the browser without proper sanitization, allowing HTML and JavaScript injection. WordPress plugins that handle user reviews are particularly susceptible to XSS vulnerabilities due to the nature of processing and displaying user-generated content.

Attack Vector

The attack vector for this Reflected XSS vulnerability involves an attacker crafting a malicious URL containing JavaScript payloads in vulnerable parameters. When an authenticated WordPress user or administrator clicks the malicious link, the script executes in their browser context. The attacker can then steal session cookies, perform actions on behalf of the victim, or redirect them to malicious sites.

The vulnerability can be exploited through specially crafted GET or POST parameters that are reflected in the plugin's output without proper encoding. Attackers typically distribute these malicious links through phishing emails, social media, or by injecting them into compromised websites.

Detection Methods for CVE-2025-23739

Indicators of Compromise

• Unusual URL parameters containing JavaScript code such as <script>, javascript:, or encoded variants in requests to WordPress pages utilizing the WP Ultimate Reviews FREE plugin
• Web server logs showing requests with XSS payloads targeting review-related endpoints
• Reports from users about unexpected browser behavior or redirects when interacting with review functionality
• Browser developer tools showing unexpected inline scripts executing from review page contexts

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common XSS payload patterns in URL parameters and POST data
• Deploy SentinelOne Singularity Platform for endpoint detection and response to identify malicious script execution attempts
• Monitor WordPress plugin activity logs for suspicious review submissions or parameter manipulation
• Utilize browser-based security tools that detect and report Content Security Policy violations

Monitoring Recommendations

• Enable comprehensive logging for all WordPress plugin interactions, particularly those handling user input
• Configure real-time alerting for detection of XSS payload patterns in web traffic
• Regularly audit WordPress access logs for anomalous requests targeting the wp-ultimate-reviews-free plugin endpoints
• Implement Content Security Policy headers to restrict inline script execution and report violations

How to Mitigate CVE-2025-23739

Immediate Actions Required

• Deactivate and remove the WP Ultimate Reviews FREE plugin (wp-ultimate-reviews-free) from all WordPress installations immediately
• Audit web server logs for evidence of exploitation attempts targeting this plugin
• Consider implementing a Web Application Firewall with XSS protection rules as an additional layer of defense
• Review all user sessions and force re-authentication for WordPress administrators

Patch Information

As of the last update, the vulnerability affects WP Ultimate Reviews FREE versions through 1.0.2. Website administrators should check the Patchstack vulnerability database for the latest patching information and vendor response. If no patched version is available, removal of the plugin is strongly recommended.

Workarounds

• Remove the WP Ultimate Reviews FREE plugin entirely until a security patch is released
• Implement Content Security Policy headers to mitigate the impact of XSS attacks by restricting script execution sources
• Deploy a Web Application Firewall with rules to filter and block XSS payloads in incoming requests
• Consider migrating to an alternative, actively maintained WordPress review plugin with a strong security track record

# WordPress CLI commands to disable and remove the vulnerable plugin
# Deactivate the plugin
wp plugin deactivate wp-ultimate-reviews-free --allow-root

# Remove the plugin completely
wp plugin delete wp-ultimate-reviews-free --allow-root

# Verify removal
wp plugin list --allow-root | grep -i reviews