CVE-2013-2203 in WordPress
Summary
by MITRE
WordPress before 3.5.2, when the uploads directory forbids write access, allows remote attackers to obtain sensitive information via an invalid upload request, which reveals the absolute path in an XMLHttpRequest error message.
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Analysis
by VulDB Data Team • 01/03/2022
This vulnerability exists in WordPress versions prior to 3.5.2 and represents a sensitive information disclosure flaw that can be exploited by remote attackers. The issue occurs specifically when the uploads directory is configured to forbid write access, creating a scenario where malicious actors can manipulate upload requests to extract system information. The vulnerability stems from improper error handling in the file upload process, where the system reveals the absolute file path in XMLHttpRequest error messages when invalid upload attempts are made. This type of information disclosure can provide attackers with critical system details that aid in further exploitation attempts. The flaw aligns with CWE-209, which addresses the improper handling of exceptions and error messages that can reveal sensitive information about the system. From an operational perspective, this vulnerability significantly increases the attack surface for WordPress installations, as the revealed absolute paths can be used to map the server structure, identify potential weaknesses in directory permissions, and plan more sophisticated attacks. Attackers can leverage this information to understand the system architecture and potentially identify other vulnerabilities that might exist within the same environment.
The technical implementation of this vulnerability involves the WordPress upload functionality failing to sanitize error messages properly when write access is denied to the uploads directory. When an attacker submits an invalid upload request, the system generates an XMLHttpRequest error that inadvertently includes the absolute path to the WordPress installation directory. This occurs because the error handling code does not properly filter or sanitize the output before presenting it to the user. The vulnerability can be exploited through standard web browser interactions without requiring authentication or special privileges. The ATT&CK framework categorizes this under T1083 (File and Directory Discovery) and T1213 (Data from Information Repositories) as it enables attackers to gather system information and potentially access additional sensitive data repositories. The impact extends beyond simple information disclosure, as the revealed paths can be used in conjunction with other vulnerabilities to escalate privileges or gain deeper system access.
The operational impact of this vulnerability is significant for WordPress installations that rely on restrictive upload directory permissions as part of their security strategy. Organizations using affected WordPress versions may unknowingly expose critical system paths that can be used to bypass other security controls or to plan more targeted attacks against their infrastructure. The vulnerability demonstrates poor input validation and error handling practices that can be exploited to gather reconnaissance information without triggering security alerts. System administrators should be particularly concerned as this vulnerability can persist undetected for extended periods, allowing attackers to systematically map the server environment. The risk is amplified when combined with other vulnerabilities that might exist in the same environment, as the revealed paths can help attackers identify potential attack vectors that would otherwise remain hidden. Security teams must consider this vulnerability as part of their threat modeling exercises and ensure that proper patch management procedures are in place to address such issues promptly. The remediation strategy should include immediate upgrading to WordPress version 3.5.2 or later, which includes proper error message sanitization, and implementation of additional security controls such as web application firewalls that can detect and block suspicious upload attempts.
Organizations should also implement comprehensive monitoring solutions that can detect abnormal upload patterns and error message generation, as these activities may indicate exploitation attempts. The vulnerability highlights the importance of proper error handling in web applications and demonstrates how seemingly benign error messages can become security risks when they contain system-specific information. Regular security assessments should include testing for similar information disclosure vulnerabilities in other web applications and services within the environment. The fix implemented in WordPress 3.5.2 addresses the root cause by ensuring that error messages do not contain absolute file paths or system-specific information, thereby preventing attackers from obtaining sensitive information through this vector. This vulnerability serves as a reminder that security considerations must be integrated throughout the application development lifecycle, particularly in error handling and logging mechanisms that are often overlooked during initial development phases.