CVE-2005-0613 in FCKeditor
Summary
by MITRE
Unknown vulnerability in FCKeditor 2.0 RC2, when used with PHP-Nuke, allows remote attackers to upload arbitrary files.
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Analysis
by VulDB Data Team • 07/28/2025
The vulnerability identified as CVE-2005-0613 represents a critical security flaw in FCKeditor version 2.0 RC2 when integrated with PHP-Nuke content management systems. This issue stems from inadequate input validation and file upload restrictions within the editor's functionality, creating a pathway for malicious actors to bypass security controls and execute unauthorized file operations. The vulnerability specifically affects web applications that utilize FCKeditor as their rich text editor component, particularly those running on PHP-Nuke platforms where the editor's upload capabilities are exposed to end users without proper sanitization mechanisms.
The technical root cause of this vulnerability lies in the editor's failure to properly validate file types and content during the upload process. When FCKeditor is configured to allow file uploads through PHP-Nuke interfaces, it accepts user-supplied file names and content without implementing sufficient checks to prevent the upload of potentially malicious files. This weakness creates an environment where attackers can craft specially formatted requests that bypass normal upload restrictions, enabling them to deposit executable scripts or other harmful content onto the target server. The vulnerability operates at the application layer and can be exploited through HTTP requests that target the editor's upload functionality, making it particularly dangerous in web environments where user input is not properly sanitized.
The operational impact of this vulnerability extends far beyond simple unauthorized file uploads, as it can lead to complete system compromise and unauthorized access to sensitive data. Attackers exploiting this vulnerability can upload web shells, malicious scripts, or other payload files that allow them to execute arbitrary commands on the compromised server. This capability enables threat actors to gain persistent access to the system, potentially leading to data theft, service disruption, or further lateral movement within the network infrastructure. The vulnerability is particularly concerning in enterprise environments where PHP-Nuke installations may host sensitive corporate information or serve as part of larger web application architectures.
Organizations utilizing FCKeditor 2.0 RC2 with PHP-Nuke should implement immediate mitigations to address this vulnerability. The primary recommendation involves upgrading to a patched version of FCKeditor that includes proper file type validation and content sanitization mechanisms. Additionally, administrators should implement strict file upload restrictions, including whitelisting approved file extensions and implementing content-based file validation. Network-level controls such as web application firewalls can provide additional protection by monitoring and filtering suspicious upload requests. The vulnerability aligns with CWE-434, which describes "Unrestricted Upload of File with Dangerous Type," and represents a common attack pattern categorized under ATT&CK technique T1195.101, focusing on content injection attacks through web application interfaces. Security teams should also consider implementing regular security assessments and penetration testing to identify similar vulnerabilities in other components of their web application stack.