CVE-2026-25329: Quiz And Survey Master Auth Bypass Flaw

CVE-2026-25329 Overview

CVE-2026-25329 is a Missing Authorization vulnerability affecting the Quiz And Survey Master WordPress plugin (quiz-master-next) developed by ExpressTech Systems. This broken access control flaw allows attackers to exploit incorrectly configured access control security levels, potentially enabling unauthorized actions within the plugin's functionality.

The vulnerability stems from CWE-862 (Missing Authorization), indicating that the plugin fails to properly verify user permissions before allowing certain operations. This type of flaw can enable unauthenticated or low-privileged users to perform actions that should be restricted to administrators or other privileged roles.

Critical Impact

Attackers can bypass access control mechanisms to perform unauthorized operations within Quiz And Survey Master, potentially compromising quiz data, survey results, or plugin settings.

Affected Products

• Quiz And Survey Master (quiz-master-next) versions through 10.3.4
• WordPress installations running vulnerable versions of the plugin
• All websites using ExpressTech Systems Quiz And Survey Master plugin prior to patched version

Discovery Timeline

• 2026-02-19 - CVE CVE-2026-25329 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2026-25329

Vulnerability Analysis

This vulnerability represents a classic broken access control issue where the Quiz And Survey Master plugin fails to implement proper authorization checks. When a WordPress plugin lacks adequate permission validation, attackers can directly access functionality that should be protected, bypassing the intended security model.

Missing Authorization vulnerabilities (CWE-862) occur when software does not perform an authorization check when an actor attempts to access a resource or perform an action. In the context of WordPress plugins, this typically manifests as AJAX handlers, REST API endpoints, or administrative functions that can be invoked without proper capability checks.

Root Cause

The root cause is the absence of proper authorization verification within the Quiz And Survey Master plugin. WordPress provides functions like current_user_can() to verify user capabilities before performing sensitive operations. When these checks are missing or improperly implemented, unauthorized users can access restricted functionality.

The plugin appears to have endpoints or functions that fail to validate whether the requesting user has appropriate permissions, allowing attackers to exploit incorrectly configured access control security levels to perform actions beyond their authorized scope.

Attack Vector

The attack vector for this vulnerability involves sending crafted requests to vulnerable plugin endpoints without proper authentication or with insufficient privileges. An attacker could potentially:

1. Identify unprotected AJAX actions or REST API endpoints exposed by the plugin
2. Craft requests that bypass normal access control flows
3. Execute administrative functions or access sensitive data without proper authorization

The vulnerability can be exploited by directly invoking plugin functionality through WordPress's AJAX handler (admin-ajax.php) or REST API endpoints without the necessary permission checks being enforced. For detailed technical information, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2026-25329

Indicators of Compromise

• Unexpected modifications to quiz or survey configurations without corresponding administrator activity
• Unusual AJAX requests to Quiz And Survey Master plugin endpoints from unauthenticated sessions
• Access logs showing requests to plugin-specific endpoints from unauthorized IP addresses or user sessions
• Changes to quiz results, survey responses, or plugin settings without audit trail entries

Detection Strategies

• Monitor WordPress access logs for suspicious requests to /wp-admin/admin-ajax.php containing Quiz And Survey Master action parameters
• Implement Web Application Firewall (WAF) rules to detect and block unauthorized access attempts to plugin endpoints
• Review WordPress user activity logs for actions performed without corresponding authenticated sessions
• Deploy file integrity monitoring to detect unauthorized changes to plugin files or database entries

Monitoring Recommendations

• Enable detailed logging for all Quiz And Survey Master plugin activities
• Configure alerts for administrative actions performed by non-administrator users
• Monitor for bulk data access or export operations from unexpected sources
• Implement rate limiting on plugin AJAX endpoints to detect automated exploitation attempts

How to Mitigate CVE-2026-25329

Immediate Actions Required

• Update Quiz And Survey Master plugin to a version newer than 10.3.4 that addresses this vulnerability
• Review WordPress user roles and capabilities to ensure minimum necessary privileges
• Audit recent plugin activity logs for signs of unauthorized access
• Consider temporarily disabling the plugin if an update is not immediately available and the functionality is not critical

Patch Information

ExpressTech Systems should release a patched version of Quiz And Survey Master that properly implements authorization checks. Website administrators should monitor the WordPress plugin repository and the Patchstack advisory for update availability.

When updating, verify the plugin version is higher than 10.3.4 and review the changelog to confirm the authorization vulnerability has been addressed.

Workarounds

• Implement Web Application Firewall rules to restrict access to Quiz And Survey Master AJAX and REST endpoints
• Use WordPress security plugins to add additional capability checks on plugin actions
• Limit access to the WordPress admin area by IP address if feasible
• Consider using a WordPress security plugin that provides virtual patching capabilities for known vulnerabilities

# Configuration example - Restrict access to WordPress admin-ajax.php for specific actions
# Add to .htaccess or nginx configuration

# Apache .htaccess example - Log and monitor quiz-master-next requests
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{REQUEST_URI} ^/wp-admin/admin-ajax\.php
    RewriteCond %{QUERY_STRING} action=.*qsm.* [NC]
    RewriteRule .* - [E=QSM_REQUEST:1]
</IfModule>

# Nginx example - Rate limit plugin endpoints
# limit_req_zone $binary_remote_addr zone=qsm_limit:10m rate=10r/m;
# location ~ ^/wp-admin/admin-ajax\.php {
#     if ($arg_action ~* "qsm") {
#         limit_req zone=qsm_limit burst=5;
#     }
# }