CVE-2025-14853: WordPress LEAV Plugin CSRF Vulnerability

CVE-2025-14853 Overview

The LEAV Last Email Address Validator plugin for WordPress contains a Cross-Site Request Forgery (CSRF) vulnerability in versions 1.7.1 and earlier. This security flaw exists due to missing or incorrect nonce validation on the display_settings_page function within the plugin's settings page implementation. The vulnerability enables unauthenticated attackers to modify plugin settings through forged requests when they successfully trick a site administrator into performing an action, such as clicking on a malicious link.

Critical Impact

Unauthenticated attackers can manipulate plugin settings without authorization, potentially disabling email validation protections or altering plugin behavior to facilitate further attacks on WordPress sites.

Affected Products

• LEAV Last Email Address Validator plugin for WordPress versions <= 1.7.1

Discovery Timeline

• 2026-01-16 - CVE-2025-14853 published to NVD
• 2026-01-16 - Last updated in NVD database

Technical Details for CVE-2025-14853

Vulnerability Analysis

This vulnerability stems from inadequate implementation of WordPress's built-in CSRF protection mechanisms. WordPress provides nonce (number used once) tokens to protect form submissions and AJAX requests from cross-site request forgery attacks. The LEAV Last Email Address Validator plugin fails to properly validate these nonce tokens in its display_settings_page function, which handles the plugin's administrative settings interface.

The vulnerability allows attackers to craft malicious web pages or links that, when visited by an authenticated administrator, will submit unauthorized requests to the WordPress admin interface. Since the plugin does not verify the authenticity of the request origin, these forged requests are processed as legitimate administrative actions.

Root Cause

The root cause is CWE-352: Cross-Site Request Forgery (CSRF). The display_settings_page function located in leav-settings-page.inc.php does not implement proper nonce verification using WordPress functions like wp_verify_nonce() or check_admin_referer(). This oversight allows form submissions to be accepted without validating that the request originated from a legitimate admin session.

Attack Vector

The attack requires network access and user interaction. An attacker must craft a malicious webpage containing a hidden form that targets the vulnerable settings endpoint. The attacker then needs to convince an authenticated WordPress administrator to visit this malicious page while logged into their WordPress site. When the administrator visits the page, their browser automatically sends the forged request with their existing authentication cookies, allowing the attacker's changes to be applied to the plugin settings.

The vulnerability affects the settings page implementation as documented in the WordPress Plugin Code Reference for the LEAV settings page. Without proper nonce validation, any authenticated session can be exploited to modify plugin configurations.

Detection Methods for CVE-2025-14853

Indicators of Compromise

• Unexpected changes to LEAV Last Email Address Validator plugin settings without administrator action
• Web server logs showing POST requests to plugin settings pages from external referrers
• Administrator reports of unusual behavior after clicking links from untrusted sources
• Plugin configuration changes that disable or alter email validation rules

Detection Strategies

• Monitor WordPress admin activity logs for settings changes to the LEAV plugin
• Implement web application firewall rules to detect CSRF attack patterns targeting WordPress admin endpoints
• Review HTTP referrer headers in access logs for requests to plugin settings pages
• Deploy browser-based security extensions that warn administrators about potential CSRF attacks

Monitoring Recommendations

• Enable comprehensive WordPress audit logging to track all plugin configuration changes
• Configure alerts for any modifications to the LEAV plugin settings outside of scheduled maintenance windows
• Regularly review the plugin's current configuration against a known-good baseline
• Monitor for unusual administrator session activity patterns

How to Mitigate CVE-2025-14853

Immediate Actions Required

• Update the LEAV Last Email Address Validator plugin to the latest version once a patch is available
• Restrict access to the WordPress admin panel to trusted IP addresses where possible
• Educate administrators about phishing risks and the importance of not clicking untrusted links while logged into WordPress
• Consider temporarily deactivating the plugin until a security update is released

Patch Information

Check the Wordfence Vulnerability Report for the latest patch status and security updates for this vulnerability. Review the plugin's changelog on the WordPress plugin repository for version information that addresses this CSRF vulnerability.

Workarounds

• Implement additional CSRF protection at the web server level using security headers and WAF rules
• Use a WordPress security plugin that provides CSRF protection for vulnerable endpoints
• Limit administrator sessions to short timeouts to reduce the window of opportunity for CSRF attacks
• Consider using browser isolation or separate browser profiles for WordPress administration tasks

# WordPress security hardening - add to wp-config.php
# Force SSL for admin and login pages
define('FORCE_SSL_ADMIN', true);

# Limit login session duration (in seconds)
define('AUTH_COOKIE_EXPIRATION', 3600);