CVE-2018-25352: WordPress Form Builder Lite SQLi Flaw

CVE-2018-25352 Overview

CVE-2018-25352 is a SQL injection vulnerability in the WordPress Ultimate Form Builder Lite plugin, affecting versions 1.3.7 and below. Authenticated attackers can manipulate database queries by injecting SQL code through the entry_id POST parameter. The attack targets the admin-ajax.php endpoint using the ufbl_get_entry_detail_action action. Successful exploitation allows extraction of database contents, modification of stored records, and privilege escalation within the WordPress site. The flaw maps to [CWE-89] Improper Neutralization of Special Elements used in an SQL Command.

Critical Impact

Authenticated attackers can extract sensitive data, modify WordPress records, and escalate privileges by injecting SQL through the entry_id parameter at admin-ajax.php.

Affected Products

• WordPress Ultimate Form Builder Lite plugin version 1.3.7
• WordPress Ultimate Form Builder Lite plugin versions prior to 1.3.7
• WordPress installations using the affected plugin with authenticated user access enabled

Discovery Timeline

• 2026-05-23 - CVE CVE-2018-25352 published to NVD
• 2026-05-26 - Last updated in NVD database

Technical Details for CVE-2018-25352

Vulnerability Analysis

The vulnerability resides in the AJAX handler registered for the ufbl_get_entry_detail_action action within the Ultimate Form Builder Lite plugin. The handler accepts an entry_id POST parameter and concatenates it directly into a SQL query without parameterization or sanitization. An authenticated attacker submitting a crafted POST request to /wp-admin/admin-ajax.php can break out of the intended query context and append arbitrary SQL clauses.

Because the injection occurs server-side against the WordPress database, attackers can read content from the wp_users, wp_usermeta, and wp_options tables. This exposes password hashes, secret keys, and session tokens. With UPDATE-style payloads or stacked subqueries, attackers can also modify the wp_capabilities meta entry to elevate a subscriber account to administrator.

Root Cause

The root cause is the absence of prepared statements or input validation on the entry_id parameter before it reaches the database layer. The plugin trusts authenticated input and passes the value into $wpdb->get_results() through string concatenation. WordPress provides $wpdb->prepare() for safe parameter binding, but the affected handler does not use it.

Attack Vector

The attack vector is network-based and requires an authenticated session at any privilege level. An attacker sends a POST request to wp-admin/admin-ajax.php containing action=ufbl_get_entry_detail_action and a malicious entry_id payload. The payload uses UNION-based or time-based blind techniques to exfiltrate data. Public exploit code is available through Exploit-DB entry 44884 and the VulnCheck advisory.

Detection Methods for CVE-2018-25352

Indicators of Compromise

• POST requests to /wp-admin/admin-ajax.php containing action=ufbl_get_entry_detail_action paired with non-numeric entry_id values
• HTTP request bodies containing SQL keywords such as UNION, SELECT, SLEEP, or INFORMATION_SCHEMA in the entry_id parameter
• Unexpected reads against the wp_users or wp_usermeta tables originating from PHP worker processes
• New administrator accounts or modifications to wp_capabilities meta records following plugin AJAX activity

Detection Strategies

• Inspect web server access logs for POST requests to admin-ajax.php correlated with the ufbl_get_entry_detail_action action
• Deploy web application firewall rules that flag SQL metacharacters in plugin AJAX parameters
• Enable MySQL general query logging temporarily on staging systems to identify malformed queries from the plugin
• Hunt for authentication anomalies, such as low-privilege accounts performing administrative actions shortly after AJAX traffic

Monitoring Recommendations

• Forward WordPress, PHP-FPM, and database logs to a centralized analytics platform for correlation
• Alert on creation of administrator-level users outside normal change windows
• Baseline expected admin-ajax.php request volume per authenticated user and alert on deviations
• Monitor for outbound data transfers from web servers that exceed historical norms, indicating possible bulk extraction

How to Mitigate CVE-2018-25352

Immediate Actions Required

• Update the Ultimate Form Builder Lite plugin to the latest available version through the WordPress plugin manager
• Audit the wp_users and wp_usermeta tables for unauthorized administrator accounts or modified capabilities
• Rotate WordPress secret keys in wp-config.php and force password resets for all users
• Restrict registration and limit which authenticated roles can reach plugin AJAX endpoints

Patch Information

Versions above 1.3.7 of Ultimate Form Builder Lite address the SQL injection by sanitizing the entry_id parameter. Site administrators should apply the latest plugin release from the WordPress plugin repository. If the plugin is no longer maintained or actively used, remove it entirely from the /wp-content/plugins/ directory. Refer to the VulnCheck advisory for vendor remediation details.

Workarounds

• Deactivate and remove the Ultimate Form Builder Lite plugin until a patched version is installed
• Deploy a WordPress-aware web application firewall ruleset that blocks SQL keywords in plugin AJAX parameters
• Restrict admin-ajax.php access for the ufbl_get_entry_detail_action action using server-level rules
• Enforce least-privilege roles and disable open user registration to limit the authenticated attack surface

# Example Nginx rule to block suspicious entry_id payloads targeting the vulnerable action
location = /wp-admin/admin-ajax.php {
    if ($request_method = POST) {
        if ($request_body ~* "action=ufbl_get_entry_detail_action.*entry_id=[^&]*(union|select|sleep|information_schema|--)") {
            return 403;
        }
    }
    include fastcgi_params;
    fastcgi_pass php-fpm;
}