CVE-2025-23555: Ui Slider Filter By Price XSS Vulnerability

CVE-2025-23555 Overview

CVE-2025-23555 is a Reflected Cross-Site Scripting (XSS) vulnerability affecting the WordPress "Ui Slider Filter By Price" plugin developed by chenyenming. This vulnerability allows attackers to inject malicious scripts into web pages viewed by unsuspecting users, potentially leading to session hijacking, credential theft, and unauthorized actions performed on behalf of authenticated users.

The vulnerability stems from improper neutralization of user-supplied input during web page generation (CWE-79). When exploited, an attacker can craft malicious URLs containing JavaScript payloads that execute in the context of a victim's browser session when they click the link.

Critical Impact

Successful exploitation enables attackers to steal session cookies, redirect users to malicious websites, deface web content, and perform actions on behalf of authenticated users including site administrators.

Affected Products

• Ui Slider Filter By Price WordPress Plugin version 1.1 and earlier
• All WordPress installations utilizing the vulnerable plugin versions
• E-commerce sites using this plugin for price range filtering functionality

Discovery Timeline

• 2025-03-03 - CVE-2025-23555 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-23555

Vulnerability Analysis

This Reflected XSS vulnerability exists within the Ui Slider Filter By Price WordPress plugin, which provides price range filtering functionality for e-commerce sites. The plugin fails to properly sanitize and escape user-controllable input before rendering it in HTML output, allowing injection of arbitrary JavaScript code.

The attack requires user interaction—a victim must click a maliciously crafted link containing the XSS payload. However, the scope is changed (as indicated by S:C in the CVSS vector), meaning the vulnerability can affect resources beyond its original security scope, potentially impacting the entire WordPress installation and other plugins.

The vulnerability affects confidentiality, integrity, and availability at a low level, enabling attackers to access limited sensitive information, make minor modifications to data, and potentially cause temporary disruptions to the affected components.

Root Cause

The root cause of CVE-2025-23555 is insufficient input validation and output encoding within the plugin's codebase. When processing URL parameters or form inputs related to price filtering, the plugin directly incorporates user-supplied values into the page without applying proper HTML entity encoding or JavaScript escaping.

WordPress provides built-in sanitization functions such as esc_html(), esc_attr(), and wp_kses() specifically designed to prevent XSS attacks. The vulnerable plugin versions fail to utilize these security functions appropriately, leaving the application susceptible to script injection.

Attack Vector

The attack is network-based and requires no authentication or special privileges. An attacker can exploit this vulnerability by constructing a malicious URL containing JavaScript code within vulnerable parameter values. The attack flow typically involves:

1. Attacker identifies the vulnerable parameter in the Ui Slider Filter By Price plugin
2. Attacker crafts a URL containing malicious JavaScript payload
3. Attacker distributes the malicious link via phishing emails, social media, or compromised websites
4. Victim clicks the link while authenticated to the target WordPress site
5. The malicious script executes in the victim's browser within the site's security context
6. Attacker gains access to session tokens, can perform actions as the victim, or redirect to credential harvesting pages

The vulnerability manifests when user-supplied input is reflected directly into the page output without proper encoding. For technical implementation details and specific vulnerable parameters, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2025-23555

Indicators of Compromise

• Unusual URL patterns in web server logs containing encoded JavaScript (e.g., %3Cscript%3E, javascript:, onerror=)
• Reports from users about unexpected browser behavior or redirects when using price filter functionality
• Web Application Firewall (WAF) alerts for XSS attack patterns targeting the ui-slider-filter-by-price plugin endpoints
• Suspicious outbound connections from user browsers to unknown domains

Detection Strategies

• Implement WAF rules specifically targeting XSS patterns in requests to WordPress plugin endpoints
• Review web server access logs for requests containing suspicious JavaScript fragments in query parameters
• Enable WordPress security plugins with real-time XSS detection capabilities
• Configure browser security headers (Content-Security-Policy) and monitor violation reports

Monitoring Recommendations

• Deploy centralized log monitoring to correlate suspicious URL patterns across all WordPress instances
• Implement Content Security Policy (CSP) reporting to detect inline script execution attempts
• Set up automated vulnerability scanning to identify installations of the affected plugin versions
• Monitor for plugin updates and security advisories from Patchstack and WordPress security sources

How to Mitigate CVE-2025-23555

Immediate Actions Required

• Identify all WordPress installations using the Ui Slider Filter By Price plugin version 1.1 or earlier
• Temporarily disable the affected plugin until a patched version is available or an alternative solution is implemented
• Deploy Web Application Firewall (WAF) rules to block common XSS payload patterns
• Review server logs for evidence of exploitation attempts

Patch Information

As of the published CVE data, the vulnerability affects Ui Slider Filter By Price plugin through version 1.1. Administrators should check the WordPress plugin repository for updated versions that address this security issue. Monitor the Patchstack Vulnerability Report for patch availability updates.

If no patch is available, consider replacing the plugin with an alternative that provides similar functionality with proper security controls.

Workarounds

• Implement Content Security Policy (CSP) headers to restrict inline script execution
• Deploy a Web Application Firewall with XSS attack pattern detection
• Consider removing or replacing the vulnerable plugin with a security-audited alternative
• Restrict access to WordPress administrative functions to trusted IP addresses

# Apache .htaccess configuration to add basic security headers
<IfModule mod_headers.c>
    # Content Security Policy to mitigate XSS
    Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';"
    
    # Prevent MIME type sniffing
    Header set X-Content-Type-Options "nosniff"
    
    # Enable XSS protection in older browsers
    Header set X-XSS-Protection "1; mode=block"
</IfModule>