CVE-2008-2146 in Wordpress
Summary
by MITRE
wp-includes/vars.php in Wordpress before 2.2.3 does not properly extract the current path from the PATH_INFO ($PHP_SELF), which allows remote attackers to bypass intended access restrictions for certain pages.
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Analysis
by VulDB Data Team • 07/31/2021
The vulnerability described in CVE-2008-2146 represents a critical path traversal and access control bypass issue within the WordPress content management system. This flaw exists in the wp-includes/vars.php file of WordPress versions prior to 2.2.3, where the application fails to properly sanitize and extract the current path from the PATH_INFO variable, which is typically represented as $PHP_SELF in PHP environments. The vulnerability stems from improper input validation and sanitization of server variables that WordPress relies upon to determine the current execution path and enforce access controls.
The technical implementation of this vulnerability exploits the insecure handling of the PATH_INFO server variable, which contains information about the path component of the current request. When WordPress processes requests, it uses this variable to determine which pages or resources should be accessible to users. The flaw occurs because the application does not adequately validate or sanitize the PATH_INFO variable before using it to construct access control decisions. This improper handling allows remote attackers to manipulate the PATH_INFO variable in a way that bypasses intended access restrictions, potentially enabling unauthorized access to protected administrative pages or sensitive functionality within the WordPress installation.
From an operational perspective, this vulnerability poses significant risks to WordPress installations, particularly those running versions before 2.2.3. Attackers could leverage this flaw to gain unauthorized access to administrative interfaces, potentially leading to complete system compromise through privilege escalation, data theft, or malicious modifications to website content. The impact extends beyond simple access bypass, as successful exploitation could enable attackers to execute arbitrary code, modify database contents, or establish persistent backdoors within the compromised WordPress environment. This vulnerability particularly affects installations where WordPress is configured to use PATH_INFO for URL routing rather than traditional query string parameters.
The mitigation strategies for CVE-2008-2146 involve immediate upgrading to WordPress version 2.2.3 or later, which contains the necessary patches to properly sanitize the PATH_INFO variable. Additionally, system administrators should implement proper input validation measures at the web server level, particularly when using PHP with PATH_INFO handling. Organizations should also consider implementing web application firewalls that can detect and block suspicious PATH_INFO manipulation attempts. This vulnerability aligns with CWE-20, which covers improper input validation, and maps to ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting, as attackers may use such bypasses to escalate privileges within compromised systems. The security community has historically emphasized the importance of proper variable sanitization in web applications, as this vulnerability demonstrates how seemingly minor input handling flaws can result in significant access control bypass capabilities.
The broader implications of this vulnerability highlight the critical importance of secure coding practices in content management systems and web applications. WordPress installations that fail to update to patched versions remain at risk for exploitation, particularly in environments where automated attack tools continuously scan for known vulnerabilities. Security monitoring should specifically include detection of anomalous PATH_INFO usage patterns, as these may indicate exploitation attempts targeting this and similar vulnerabilities. The incident underscores the necessity for regular security updates and the implementation of defense-in-depth strategies that include both application-level patches and infrastructure-level protections against path traversal attacks.