CVE-2006-0921 in FCKeditor
Summary
by MITRE
Multiple directory traversal vulnerabilities in connector.php in FCKeditor 2.0 FC, as used in products such as RunCMS, allow remote attackers to list and create arbitrary directories via a .. (dot dot) in the CurrentFolder parameter to (1) GetFoldersAndFiles and (2) CreateFolder.
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Analysis
by VulDB Data Team • 07/20/2018
The vulnerability identified as CVE-2006-0921 represents a critical directory traversal flaw in FCKeditor 2.0 FC's connector.php component, which has been widely adopted across various web applications including RunCMS. This security weakness stems from inadequate input validation mechanisms within the file handling processes of the rich text editor component. The vulnerability specifically affects the CurrentFolder parameter in two distinct functions: GetFoldersAndFiles and CreateFolder, both of which are integral to the editor's file management capabilities.
The technical implementation of this vulnerability allows malicious actors to exploit the lack of proper path validation by injecting directory traversal sequences using the .. (dot dot) notation. When an attacker submits a crafted CurrentFolder parameter containing traversal sequences, the system fails to sanitize these inputs properly, enabling unauthorized access to directories outside the intended file system scope. This flaw operates at the core of the application's file system interaction logic, where the connector.php script processes user-supplied folder paths without adequate sanitization or validation checks.
The operational impact of this vulnerability extends beyond simple directory listing capabilities, as it enables attackers to create arbitrary directories within the target system's file structure. This privilege escalation allows for potential file system manipulation, unauthorized directory creation, and in severe cases, could lead to complete system compromise if combined with other vulnerabilities. The vulnerability affects not only the immediate file system access but also poses risks to application stability and data integrity, as unauthorized directory creation could disrupt legitimate application functionality.
From a cybersecurity perspective, this vulnerability aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and represents a classic example of path traversal attacks that have been documented in the ATT&CK framework under the T1059.007 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) techniques. The flaw demonstrates the critical importance of input validation and proper access control mechanisms in web applications, particularly those handling user-supplied file paths or directory references.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and sanitization measures within the connector.php script. Organizations should implement strict path validation that prevents traversal sequences from being processed, enforce proper access controls for file system operations, and establish comprehensive monitoring of file system access patterns. Additionally, the recommended remediation includes upgrading to patched versions of FCKeditor or implementing web application firewalls that can detect and block malicious traversal attempts. The vulnerability also underscores the necessity of regular security audits and input validation testing to identify similar weaknesses in other components of the application stack, particularly in legacy systems that may contain unpatched vulnerable libraries.