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

bash

# 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;
}