CVE-2008-2392 in WordPress
Summary
by MITRE
Unrestricted file upload vulnerability in WordPress 2.5.1 and earlier might allow remote authenticated administrators to upload and execute arbitrary PHP files via the Upload section in the Write Tabs area of the dashboard.
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Analysis
by VulDB Data Team • 09/25/2018
The vulnerability identified as CVE-2008-2392 represents a critical security flaw in WordPress versions 2.5.1 and earlier that stems from insufficient input validation during file upload operations. This weakness specifically affects the media upload functionality within the WordPress administrative dashboard, creating a pathway for authenticated attackers with administrator privileges to bypass security controls and execute malicious code on the affected system. The vulnerability resides in the unrestricted file upload mechanism that fails to properly validate file types and contents, allowing attackers to upload PHP files that can be executed within the web server context.
From a technical perspective, this vulnerability operates through a lack of proper file type validation and content inspection mechanisms within WordPress's upload handling code. The flaw enables attackers to upload files with .php extensions or other executable file types that are not properly filtered or restricted by the application's security controls. When these malicious files are uploaded to the server, they can be accessed through the web server's document root, allowing for arbitrary code execution. This represents a classic unrestricted file upload vulnerability that aligns with CWE-434, which specifically addresses the issue of uploading files that are not properly validated for content type and file extension.
The operational impact of this vulnerability is severe and far-reaching for WordPress installations running affected versions. An authenticated administrator with sufficient privileges can leverage this vulnerability to upload malicious PHP scripts that can perform various malicious activities including but not limited to data exfiltration, privilege escalation, backdoor installation, and server compromise. The attacker can execute commands with the privileges of the web server process, potentially leading to full system compromise. This vulnerability essentially transforms a legitimate administrative function into a weaponized attack vector, as it allows attackers to bypass traditional security controls that typically protect against such attacks.
The exploitation of this vulnerability follows established attack patterns that align with several ATT&CK framework techniques including T1059 for command and scripting interpreter and T1078 for valid accounts. The attack typically begins with an authenticated administrator gaining access to the WordPress dashboard, followed by uploading a malicious PHP file through the unrestricted upload functionality. Once uploaded, the attacker can access the file through a web browser or other means to execute the malicious code. This vulnerability demonstrates the critical importance of proper input validation and the principle of least privilege in web application security. Organizations should implement multiple layers of defense including file type validation, content inspection, and proper access controls to prevent such attacks from succeeding.
Mitigation strategies for this vulnerability include immediate upgrade to WordPress 2.5.2 or later versions where the issue has been patched, along with implementation of additional security controls such as restrictive file type validation, content inspection of uploaded files, and proper access controls. The patch for this vulnerability specifically addresses the upload validation mechanism to ensure that only safe file types are accepted and that uploaded files are properly sanitized before being stored on the server. Organizations should also consider implementing web application firewalls, regular security audits, and monitoring for suspicious file upload activities to further reduce the risk of exploitation. The vulnerability serves as a reminder of the critical importance of keeping web applications updated and implementing robust security controls to prevent unauthorized code execution.