CVE-2025-25133: WP Frontend Submit XSS Vulnerability

CVE-2025-25133 Overview

CVE-2025-25133 is a reflected Cross-Site Scripting (XSS) vulnerability [CWE-79] affecting the WP Frontend Submit WordPress plugin by newbiesup. The flaw exists in all versions up to and including 1.1.0. The plugin fails to properly neutralize user-supplied input during web page generation, allowing attackers to inject and execute arbitrary JavaScript in a victim's browser session.

Exploitation requires user interaction, typically through a crafted link. Successful attacks execute in the context of the targeted WordPress site, potentially leading to session theft, credential harvesting, or actions performed on behalf of authenticated users including administrators.

Critical Impact

Attackers can execute arbitrary JavaScript in victim browsers by tricking users into clicking malicious links, enabling session hijacking and unauthorized actions against the affected WordPress site.

Affected Products

• newbiesup WP Frontend Submit plugin for WordPress
• All versions from n/a through 1.1.0
• WordPress installations with the vulnerable plugin enabled

Discovery Timeline

• 2025-03-03 - CVE-2025-25133 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-25133

Vulnerability Analysis

The vulnerability stems from improper neutralization of input during web page generation within the WP Frontend Submit plugin. User-controlled parameters are reflected back into HTML responses without proper output encoding or input sanitization. This permits attacker-supplied scripts to render and execute in the browser context of any user who visits a crafted URL.

The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation). The scope is changed, meaning the injected script can affect resources beyond the vulnerable component's security authority. Confidentiality, integrity, and availability are each impacted at a low level.

The EPSS score is 0.232% (percentile 45.918), indicating a low predicted likelihood of exploitation at scale. However, reflected XSS in WordPress plugins is frequently weaponized in targeted phishing campaigns against site administrators.

Root Cause

The plugin processes request parameters and echoes them into the response page without applying WordPress sanitization functions such as esc_html(), esc_attr(), or wp_kses(). The absence of contextual output encoding causes the browser to parse attacker-supplied content as executable script rather than literal text.

Attack Vector

The attack vector is network-based with low complexity and no privileges required. User interaction is required, typically clicking a crafted link delivered via phishing email, malicious advertisement, or another web page. When the victim loads the URL, the malicious payload reflects into the response and executes within the trusted origin of the WordPress site.

If an authenticated administrator triggers the payload, the attacker can perform privileged actions including creating new admin accounts, modifying plugin settings, or injecting persistent backdoors. Refer to the Patchstack advisory for additional technical details.

Detection Methods for CVE-2025-25133

Indicators of Compromise

• Inbound HTTP requests to WP Frontend Submit endpoints containing script tags, javascript: URIs, or HTML event handler attributes such as onerror= and onload=
• Referer headers originating from untrusted domains pointing to plugin URLs with encoded payloads
• Unexpected creation of WordPress administrator accounts or modification of plugin settings shortly after a user clicked an external link
• Browser console errors or content security policy violations on pages served by the plugin

Detection Strategies

• Inspect web server access logs for query strings containing URL-encoded <script>, %3Cscript, or HTML attribute injection patterns targeting the plugin's request handlers
• Deploy a Web Application Firewall (WAF) rule set that flags reflected XSS signatures against WordPress plugin paths
• Audit installed plugin versions across managed WordPress fleets to identify instances of WP Frontend Submit at or below version 1.1.0

Monitoring Recommendations

• Enable WordPress audit logging to capture configuration changes, user creation events, and plugin activity
• Monitor outbound network connections from administrator browser sessions for anomalous requests to external domains
• Alert on suspicious POST requests to wp-admin endpoints originating from authenticated sessions immediately after the user followed an external link

How to Mitigate CVE-2025-25133

Immediate Actions Required

• Disable or remove the WP Frontend Submit plugin until a patched release is verified and available
• Force a password reset for all WordPress administrator accounts on affected sites
• Invalidate active sessions through wp_logout_url() enforcement or session token rotation
• Review recent administrative actions in WordPress audit logs for unauthorized changes

Patch Information

No fixed version is identified in the available CVE data. The advisory indicates the vulnerability affects all versions through 1.1.0. Administrators should monitor the Patchstack vulnerability database and the plugin's WordPress.org page for an official patched release.

Workarounds

• Deploy a WAF with rules that block reflected XSS payloads targeting WP Frontend Submit endpoints
• Implement a strict Content Security Policy (CSP) header that disallows inline scripts and restricts script sources to trusted origins
• Restrict plugin functionality to authenticated users only, reducing the attack surface exposed to anonymous visitors
• Train administrators to avoid clicking unsolicited links pointing to the WordPress site, particularly when authenticated

# Example Content Security Policy header for WordPress (nginx)
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self';" always;