CVE-2007-4894 in Wordpress
Summary
by MITRE
Multiple SQL injection vulnerabilities in Wordpress before 2.2.3 and Wordpress multi-user (MU) before 1.2.5a allow remote attackers to execute arbitrary SQL commands via the post_type parameter to the pingback.extensions.getPingbacks method in the XMLRPC interface, and other unspecified parameters related to "early database escaping" and missing validation of "query string like parameters."
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Analysis
by VulDB Data Team • 07/26/2019
The vulnerability described in CVE-2007-4894 represents a critical security flaw affecting WordPress installations prior to version 2.2.3 and WordPress Multi-User (MU) prior to 1.2.5a. This vulnerability stems from inadequate input validation and improper database query handling within the XMLRPC interface, which serves as a communication protocol for remote management of WordPress sites. The flaw specifically targets the pingback.extensions.getPingbacks method, which is part of the XMLRPC API that allows external systems to interact with WordPress for pingback functionality. The vulnerability allows remote attackers to inject malicious SQL commands through the post_type parameter, effectively bypassing the normal security controls that protect WordPress databases from unauthorized access.
The technical root cause of this vulnerability lies in what is commonly referred to as "early database escaping" and "missing validation of query string like parameters." This pattern of implementation error creates a condition where user-supplied input is not properly sanitized before being incorporated into database queries. The vulnerability specifically affects WordPress versions that implemented an XMLRPC interface without adequate protection against SQL injection attacks. The post_type parameter, when manipulated by an attacker, can be crafted to inject malicious SQL code that executes with the privileges of the WordPress database user. This represents a classic SQL injection vulnerability that falls under CWE-89, which defines the weakness of allowing SQL commands to be executed through unescaped input. The vulnerability is particularly dangerous because it operates at the database layer, potentially allowing attackers to extract sensitive data, modify content, or even escalate privileges within the WordPress environment.
The operational impact of this vulnerability extends far beyond simple data theft, as it enables attackers to gain unauthorized access to WordPress databases and potentially compromise entire websites. The XMLRPC interface, which is commonly used for pingback functionality and remote publishing, becomes a vector for executing arbitrary SQL commands that can manipulate database records, retrieve user credentials, or even delete content. Attackers can exploit this vulnerability to perform actions such as creating new administrative accounts, modifying existing user permissions, accessing private posts and pages, or extracting sensitive information from database tables. This vulnerability particularly affects multi-user installations where the complexity of user permissions and database interactions increases the potential attack surface. The impact is amplified because XMLRPC interfaces are often enabled by default on WordPress installations, providing attackers with a readily available attack vector that requires no special prerequisites beyond basic network access to the WordPress site.
Mitigation strategies for this vulnerability require immediate patching of affected WordPress installations to version 2.2.3 or later, which includes proper input validation and escaping mechanisms for XMLRPC parameters. Organizations should also implement network-level protections such as firewall rules that restrict access to the XMLRPC interface, particularly when it is not required for legitimate operations. The implementation of proper input validation and parameter sanitization should be enforced throughout the WordPress codebase, with particular attention to how query string parameters are processed before being used in database queries. Security monitoring should be enhanced to detect unusual patterns of XMLRPC requests that may indicate exploitation attempts. Additionally, administrators should conduct regular security audits to ensure that all WordPress installations are running patched versions and that unnecessary features such as XMLRPC are disabled when not required. This vulnerability demonstrates the importance of following secure coding practices and adheres to ATT&CK technique T1071.004, which involves the use of application layer protocols for command and control operations, as attackers can leverage XMLRPC functionality to execute malicious commands on compromised systems. The vulnerability also highlights the necessity of proper database access controls and the principle of least privilege, ensuring that database users have only the permissions necessary for their specific functions.