CVE-2006-6376 in Simple File Manager
Summary
by MITRE
Multiple directory traversal vulnerabilities in fm.php in Simple File Manager (SFM) 0.24a allow remote attackers to use ".." sequences to (1) read arbitrary files via the filename parameter in a download action, (2) delete arbitrary files via the delete parameter, and (3) modify arbitrary files via the edit parameter, which can be leveraged to execute arbitrary code.
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Analysis
by VulDB Data Team • 12/21/2024
The vulnerability described in CVE-2006-6376 represents a critical directory traversal flaw in Simple File Manager version 0.24a that exposes multiple attack vectors through improper input validation. This issue stems from the application's failure to properly sanitize user-supplied input parameters, specifically the filename, delete, and edit parameters in the fm.php script. The vulnerability allows remote attackers to manipulate file system access by exploiting the ".." sequences that are commonly used to navigate directory structures. According to CWE-22, this corresponds to Improper Limitation of a Pathname to a Restricted Directory, which is a fundamental weakness in path validation that enables attackers to access files outside the intended directory scope.
The technical exploitation of this vulnerability occurs through the manipulation of file system path parameters that are directly passed to file operations without adequate sanitization or validation. When an attacker submits malicious ".." sequences through the filename parameter during a download action, the application processes these sequences without proper restriction, allowing access to files outside the designated file manager directory. Similarly, the delete and edit parameters suffer from identical vulnerabilities, enabling attackers to perform destructive operations on arbitrary files within the system's file structure. This vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: PowerShell and T1566.001 for Phishing: Spearphishing Attachment, as attackers can leverage these flaws to gain unauthorized access and potentially execute malicious code through file manipulation.
The operational impact of this vulnerability extends beyond simple unauthorized file access, as it provides attackers with the capability to modify, delete, or read sensitive system files that may contain configuration data, user credentials, or application logic. This exposure creates a pathway for privilege escalation and persistent access, as attackers can modify system files or inject malicious code into the application's file structure. The vulnerability's severity is compounded by its remote exploitability, meaning that attackers do not require local system access to leverage these flaws, making the attack surface significantly broader. Organizations using Simple File Manager 0.24a are at risk of complete system compromise, as the vulnerability can be exploited through web-based attacks without requiring physical access or specialized tools. The potential for code execution through file modification operations makes this particularly dangerous, as it enables attackers to establish backdoors or deploy additional malicious payloads within the compromised environment.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and sanitization mechanisms within the Simple File Manager application. The most effective approach involves implementing strict path validation that prevents traversal sequences from being processed, ensuring that all file operations occur within predetermined directory boundaries. Security measures should include implementing a whitelist approach for file operations, where only explicitly allowed files and directories are accessible, and any attempt to traverse beyond these boundaries should be rejected. Additionally, the application should enforce proper access controls and authentication mechanisms to limit who can perform file operations, as well as implement logging and monitoring of file access activities to detect potential exploitation attempts. Organizations should also consider upgrading to newer versions of Simple File Manager or migrating to more secure file management solutions that have addressed these fundamental security flaws. According to industry best practices, this vulnerability should be classified as high severity and addressed with immediate priority, as it represents a clear path to system compromise through simple directory traversal techniques that have been well-known and documented for many years.