CVE-2018-16159 in Gift Vouchers Plugin
Summary
by MITRE
The Gift Vouchers plugin through 2.0.1 for WordPress allows SQL Injection via the template_id parameter in a wp-admin/admin-ajax.php wpgv_doajax_front_template request.
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Analysis
by VulDB Data Team • 03/19/2020
The vulnerability identified as CVE-2018-16159 affects the Gift Vouchers plugin version 2.0.1 and earlier for WordPress platforms, presenting a critical SQL injection flaw that could compromise the entire web application. This vulnerability specifically manifests within the wp-admin/admin-ajax.php endpoint when processing requests with the wpgv_doajax_front_template action, where the template_id parameter fails to properly sanitize user input before incorporating it into database queries. The flaw represents a classic SQL injection vulnerability that falls under CWE-89, which describes improper neutralization of special elements used in an SQL command, and aligns with ATT&CK technique T1190 for exploiting vulnerabilities in web applications.
The technical implementation of this vulnerability occurs when an attacker crafts a malicious request to the admin-ajax.php endpoint with a specially crafted template_id parameter containing SQL payload. Without proper input validation or parameterized query construction, the plugin directly incorporates this user-supplied data into SQL statements executed against the WordPress database. This allows an attacker to manipulate database queries and potentially execute arbitrary SQL commands, leading to unauthorized data access, modification, or deletion. The vulnerability is particularly dangerous because it operates through the WordPress admin interface, which typically requires authentication, but the specific endpoint may be accessible to unauthenticated users or those with limited privileges.
The operational impact of this vulnerability extends beyond simple data theft, as it could enable attackers to escalate privileges within the WordPress environment, extract sensitive user credentials, modify or delete critical website content, and potentially establish persistent access through backdoor creation. The Gift Vouchers plugin's functionality involves handling gift voucher templates, making the database queries particularly sensitive as they may contain user information, voucher details, and potentially payment-related data. Attackers could leverage this vulnerability to gain unauthorized access to customer information, manipulate voucher balances, or even take complete control of the WordPress installation. The exploitation of such a vulnerability could result in significant financial losses, data breaches, and reputational damage for organizations relying on the affected plugin.
Mitigation strategies for CVE-2018-16159 should prioritize immediate plugin updates to versions that address the SQL injection vulnerability, as the vendor has likely released patches to correct the input sanitization issues. Organizations should implement proper parameterized queries or prepared statements to prevent SQL injection, and establish input validation mechanisms that strictly filter and sanitize all user-supplied data before database processing. Network-level protections such as web application firewalls can provide additional defense-in-depth measures, while regular security audits and vulnerability assessments should be conducted to identify similar flaws in other plugins or themes. The vulnerability demonstrates the critical importance of maintaining up-to-date WordPress plugins and following secure coding practices, particularly when handling user input in database operations, aligning with security frameworks that emphasize the need for proper input validation and output encoding as primary defenses against injection attacks.