CVE-2017-16510 in WordPress
Summary
by MITRE
WordPress before 4.8.3 is affected by an issue where $wpdb->prepare() can create unexpected and unsafe queries leading to potential SQL injection (SQLi) in plugins and themes, as demonstrated by a "double prepare" approach, a different vulnerability than CVE-2017-14723.
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Analysis
by VulDB Data Team • 01/05/2023
WordPress versions prior to 4.8.3 contained a critical vulnerability in the $wpdb->prepare() function that enabled attackers to bypass intended SQL query sanitization mechanisms. This flaw specifically affected how the prepare function handled nested or repeated parameter placeholders within SQL queries, creating a pathway for malicious input to be injected into database operations. The vulnerability arose from improper handling of multiple prepare operations within the same query context, allowing attackers to manipulate the query structure through carefully crafted input parameters that were not properly escaped or validated.
The technical implementation of this vulnerability stemmed from the wpdb class's insufficient validation of prepared statement parameters when multiple placeholders were present in a single query. When plugins or themes utilized the $wpdb->prepare() function in conjunction with other query building methods, the system failed to properly sanitize subsequent parameter substitutions, creating opportunities for SQL injection attacks. This issue was distinct from CVE-2017-14723 because it focused specifically on the interaction between multiple prepare operations rather than a single flawed parameter handling mechanism. The vulnerability operated at the database abstraction layer, making it particularly dangerous as it could affect any plugin or theme that relied on WordPress's built-in database functions.
The operational impact of CVE-2017-16510 was severe for WordPress installations, as it allowed authenticated attackers with minimal privileges to execute arbitrary SQL commands against the database. This could result in data theft, unauthorized modifications, complete database compromise, or even full system takeover depending on the attacker's access level and the database configuration. The vulnerability was particularly insidious because it could be exploited through seemingly legitimate plugin or theme functionality, making detection more difficult. Attackers could leverage this weakness to extract sensitive information such as user credentials, content, and system configurations, potentially leading to persistent backdoor access or data destruction operations.
Mitigation strategies for this vulnerability required immediate patching of WordPress installations to version 4.8.3 or later, which contained the necessary fixes to properly handle nested prepare operations. Organizations should also implement comprehensive input validation and sanitization practices, ensuring that all user-supplied data is properly escaped before being incorporated into database queries. Security monitoring systems should be configured to detect unusual database query patterns that might indicate exploitation attempts. Additionally, the principle of least privilege should be enforced, limiting database user permissions to only those necessary for WordPress operations. This vulnerability aligns with CWE-89 SQL Injection and can be mapped to ATT&CK technique T1071.004 Application Layer Protocol: DNS, though the primary attack vector was through database query manipulation rather than network protocols. Organizations should also conduct thorough security audits of custom plugins and themes to ensure they do not inadvertently create similar vulnerabilities through improper use of the wpdb functions.