CVE-2025-27345: Booking Ultra Pro XSS Vulnerability

CVE-2025-27345 Overview

CVE-2025-27345 is a Reflected Cross-Site Scripting (XSS) vulnerability affecting the Deetronix Booking Ultra Pro WordPress plugin. This vulnerability stems 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.

Reflected XSS vulnerabilities occur when user-supplied data is immediately returned by a web application in error messages, search results, or other responses without proper sanitization or encoding. In this case, the booking-ultra-pro plugin fails to properly validate and sanitize user input before reflecting it back in the generated HTML output.

Critical Impact

Attackers can exploit this vulnerability to execute arbitrary JavaScript code in victims' browsers, potentially stealing session cookies, hijacking user sessions, defacing websites, or redirecting users to malicious sites.

Affected Products

• Deetronix Booking Ultra Pro WordPress Plugin versions through 1.1.19
• WordPress installations using the booking-ultra-pro plugin
• Websites with user-accessible booking functionality powered by Booking Ultra Pro

Discovery Timeline

• April 17, 2025 - CVE-2025-27345 published to NVD
• April 15, 2026 - Last updated in NVD database

Technical Details for CVE-2025-27345

Vulnerability Analysis

This vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), which encompasses Cross-Site Scripting flaws. The Booking Ultra Pro plugin, designed to provide booking functionality for WordPress websites, contains a flaw in how it processes user-supplied input parameters.

When a user interacts with the booking system, certain input parameters are reflected back into the page without adequate sanitization. This allows an attacker to craft a malicious URL containing JavaScript code that, when clicked by a victim, executes within the security context of the vulnerable website.

The reflected nature of this XSS means the payload is not stored on the server but is instead delivered through the URL itself, typically requiring social engineering to trick victims into clicking malicious links.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and output encoding within the Booking Ultra Pro plugin's request handling logic. The plugin fails to properly sanitize user-controllable input before including it in dynamically generated HTML responses. Without proper encoding of special characters such as <, >, ", and ', an attacker can break out of the intended HTML context and inject arbitrary script content.

Attack Vector

The attack vector for this Reflected XSS vulnerability involves crafting a malicious URL that contains JavaScript payload within vulnerable parameters. The attack typically proceeds as follows:

1. An attacker identifies a vulnerable parameter in the Booking Ultra Pro plugin that reflects user input without proper sanitization
2. The attacker crafts a URL containing malicious JavaScript code embedded in the vulnerable parameter
3. The attacker distributes this URL through phishing emails, social media, or other channels
4. When a victim clicks the link while authenticated to the WordPress site, the malicious script executes in their browser
5. The script can then perform actions as the victim, steal session tokens, or redirect to attacker-controlled pages

The vulnerability requires user interaction (clicking a malicious link) to exploit, but successful exploitation can lead to session hijacking, credential theft, or unauthorized actions on behalf of the victim.

Detection Methods for CVE-2025-27345

Indicators of Compromise

• Unusual URL patterns in web server logs containing encoded JavaScript or HTML tags in booking-related parameters
• Presence of suspicious scripts or iframe injections in HTTP request logs targeting the booking-ultra-pro plugin endpoints
• User reports of unexpected redirects or browser warnings when accessing booking pages
• Authentication anomalies or session theft incidents traced back to booking functionality interactions

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS payloads in URL parameters targeting WordPress plugins
• Monitor web server access logs for requests containing common XSS patterns such as <script>, javascript:, onerror=, and other event handlers
• Deploy Content Security Policy (CSP) headers to restrict script execution sources and report violations
• Utilize WordPress security plugins that scan for known vulnerable plugin versions and alert administrators

Monitoring Recommendations

• Enable detailed logging for the booking-ultra-pro plugin endpoints and monitor for anomalous request patterns
• Set up alerts for CSP violation reports that may indicate attempted XSS exploitation
• Monitor for unusual user session activity patterns that could suggest session hijacking following XSS attacks
• Regularly review plugin update notifications and security advisories from sources like Patchstack

How to Mitigate CVE-2025-27345

Immediate Actions Required

• Update the Booking Ultra Pro plugin to a version newer than 1.1.19 as soon as a patch is available
• Review and audit any custom code or configurations that interact with the booking plugin for additional input validation
• Implement Content Security Policy headers to limit the impact of potential XSS exploitation
• Consider temporarily disabling the plugin if no patch is available and booking functionality is not critical

Patch Information

Users should monitor the official WordPress plugin repository and the Patchstack Vulnerability Report for updates regarding a security patch for this vulnerability. Update to the latest version of the Booking Ultra Pro plugin once a fix has been released by Deetronix.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules to filter XSS payloads targeting the vulnerable plugin parameters
• Implement strict Content Security Policy headers to prevent inline script execution: Content-Security-Policy: default-src 'self'; script-src 'self'
• Restrict access to the booking functionality to authenticated users only where possible
• Consider using an alternative booking plugin until a patched version is released

# Configuration example - Add CSP headers in WordPress .htaccess or server config
# Apache configuration
<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>