CVE-2017-14723 in WordPress
Summary
by MITRE
Before version 4.8.2, WordPress mishandled % characters and additional placeholder values in $wpdb->prepare, and thus did not properly address the possibility of plugins and themes enabling SQL injection attacks.
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Analysis
by VulDB Data Team • 12/30/2022
The vulnerability identified as CVE-2017-14723 represents a critical SQL injection weakness in WordPress core functionality that existed prior to version 4.8.2. This flaw specifically affected the $wpdb->prepare method which serves as WordPress's primary interface for preparing SQL queries with user input. The vulnerability stemmed from inadequate handling of percent characters and additional placeholder values within the prepare function, creating a pathway for malicious actors to inject arbitrary SQL commands through improperly sanitized input.
The technical implementation of this vulnerability lies in WordPress's database abstraction layer where the $wpdb->prepare method is designed to safely escape and format SQL query parameters. However, the flaw occurred when developers or plugins utilized the prepare function with improper placeholder syntax or failed to properly escape percent characters that could be interpreted as format specifiers by the underlying database layer. This misconfiguration allowed attackers to manipulate the query structure and potentially execute unauthorized database operations.
From an operational perspective, this vulnerability posed significant risks to WordPress installations as it could be exploited by attackers to perform unauthorized database operations including data extraction, modification, or deletion. The impact extended beyond basic SQL injection to potentially enable privilege escalation attacks where attackers could gain administrative access to WordPress sites. The vulnerability was particularly dangerous because it could be triggered through various user input points within themes and plugins that improperly utilized the $wpdb->prepare function, making detection and prevention challenging for site administrators.
The flaw aligns with CWE-89 which describes improper neutralization of special elements used in an SQL command, and represents a classic case of inadequate input validation and sanitization in database query construction. From an ATT&CK framework perspective, this vulnerability maps to T1071.004 for application layer protocol and T1190 for exploit public-facing application, as attackers could leverage this weakness to gain unauthorized access to WordPress databases. The vulnerability also demonstrates the principle of least privilege violation where insufficient input validation allowed attackers to bypass normal security controls.
Mitigation strategies for CVE-2017-14723 required immediate patching to WordPress version 4.8.2 or later, which contained the necessary fixes to properly handle percent characters and placeholder values in the $wpdb->prepare function. Additionally, administrators should implement comprehensive input validation practices within their themes and plugins, ensuring that all user-supplied data is properly escaped before database insertion. Security monitoring should include detection of malformed SQL queries and unusual database access patterns. Regular security audits of third-party plugins and themes became essential as many vendors had not properly addressed this vulnerability in their code implementations. The fix implemented by WordPress developers specifically addressed the core issue by improving the internal handling of format specifiers and ensuring proper escaping of special characters in prepared statements.