CVE-2001-1131 in SlimFTPd
Summary
by MITRE
Directory traversal vulnerability in WhitSoft Development SlimFTPd 2.2 allows an attacker to read arbitrary files and directories via a ... (modified dot dot) in the CD command.
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Analysis
by VulDB Data Team • 06/09/2019
The directory traversal vulnerability identified in CVE-2001-1131 affects WhitSoft Development SlimFTPd version 2.2, representing a critical security flaw that enables unauthorized access to sensitive system files through improper input validation in the CD command. This vulnerability falls under the CWE-22 category, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw manifests when the FTP server fails to properly sanitize user input during directory change operations, allowing attackers to manipulate the CD command with malicious path sequences containing dot-dot references.
The technical implementation of this vulnerability exploits the lack of proper input validation in the FTP server's command processing mechanism. When an attacker issues a CD command with sequences such as ../../etc/passwd or similar path manipulation attempts, the server processes these inputs without adequate sanitization, allowing the traversal beyond the intended directory boundaries. This weakness enables attackers to access files outside the designated FTP root directory, potentially exposing sensitive system information including configuration files, user credentials, and other confidential data. The vulnerability specifically targets the CD command which is fundamental to FTP operations for changing directories, making it a core attack vector for unauthorized file access.
The operational impact of this vulnerability extends beyond simple file reading capabilities to encompass potential system compromise and data exfiltration. Attackers can leverage this flaw to access system configuration files, user authentication data, application source code, and other sensitive materials that may contain credentials, system architecture details, or business logic. The vulnerability enables attackers to perform reconnaissance activities that could lead to further exploitation attempts, potentially allowing them to escalate privileges or establish persistent access to the compromised system. This type of vulnerability particularly affects organizations that rely on older FTP server implementations, as SlimFTPd 2.2 represents a legacy system that may not receive regular security updates or patches.
Mitigation strategies for this vulnerability require immediate implementation of input validation controls and proper path sanitization mechanisms within the FTP server configuration. Organizations should implement strict input filtering that prevents the processing of dot-dot sequences and other path traversal attempts in directory change commands. The recommended approach includes enforcing absolute path validation that ensures all directory operations remain within designated boundaries and implementing proper access controls that limit the exposure of sensitive files. Security measures should also encompass regular patch management procedures and system updates to address known vulnerabilities in legacy FTP implementations. Additionally, network segmentation and firewall rules should be configured to restrict FTP access to authorized users and systems, reducing the attack surface for potential exploitation attempts. This vulnerability aligns with ATT&CK technique T1071.004 which covers application layer protocol: ftp, and represents a fundamental security weakness that organizations must address through comprehensive patch management and input validation strategies.