CVE-2003-1349 in NiteServer FTPd
Summary
by MITRE
Directory traversal vulnerability in NITE ftp-server (NiteServer) 1.83 allows remote attackers to list arbitrary directories via a "\.." (backslash dot dot) in the CD (CWD) command.
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Analysis
by VulDB Data Team • 07/14/2025
The vulnerability identified as CVE-2003-1349 represents a critical directory traversal flaw within the NITE ftp-server version 1.83 implementation. This security weakness specifically affects the Change Directory (CWD) command functionality, where the server fails to properly validate user input containing backslash dot dot sequences. The vulnerability stems from inadequate input sanitization mechanisms that permit malicious actors to manipulate directory navigation paths through crafted CD commands. When a remote attacker submits a command containing "\..", the server processes this input without sufficient validation, allowing unauthorized access to arbitrary directory structures within the file system. This flaw essentially enables attackers to bypass normal directory access controls and explore system directories beyond the intended scope of the FTP service. The vulnerability is classified under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. This weakness directly aligns with ATT&CK technique T1083, which describes discovering files and directories, as attackers can systematically enumerate system resources through this vulnerability. The impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to navigate the entire file system hierarchy, potentially accessing sensitive configuration files, user data, or system binaries.
The technical implementation of this vulnerability exploits the fundamental design flaw in how the NITE ftp-server handles relative path references within the CWD command. When processing a command such as "CWD \..", the server should validate that the requested path remains within the designated FTP root directory and prevent access to parent directories. However, the server's implementation fails to properly resolve or sanitize the backslash dot dot sequences, allowing the path traversal to occur. This processing error creates a situation where the server interprets the malicious input as a legitimate navigation command, resulting in directory listing operations that extend beyond the intended access boundaries. The vulnerability is particularly concerning because it operates at the protocol level of the FTP service, meaning that any client capable of sending CWD commands can potentially exploit this weakness. The flaw exists in the server's path resolution logic, where the system does not adequately check whether the requested directory path contains sequences that would allow navigation to parent directories. This represents a classic case of insufficient input validation where the server accepts user-supplied path components without proper sanitization or normalization. The implementation lacks proper boundary checking mechanisms that would normally prevent such path traversal operations.
The operational impact of CVE-2003-1349 is severe and multifaceted, as it provides attackers with comprehensive directory traversal capabilities within the affected FTP server environment. Successful exploitation allows unauthorized access to potentially sensitive files and directories, including system configuration files, user data, application files, and other resources that should remain protected. Attackers can systematically enumerate directory structures, potentially identifying valuable targets such as database files, source code repositories, or administrative configuration files. The vulnerability enables attackers to perform reconnaissance activities that would normally require legitimate access privileges, making it particularly dangerous for systems where FTP services are used for file transfers. Additionally, the ability to list arbitrary directories can lead to further exploitation opportunities, as attackers can identify other vulnerabilities or sensitive data that may exist within the traversed directories. The impact extends to data confidentiality and integrity, as unauthorized access to system directories may expose sensitive information or provide opportunities for privilege escalation. Organizations using NITE ftp-server 1.83 are at risk of unauthorized data access, potential data exfiltration, and system compromise through this vulnerability. The vulnerability also affects system availability if attackers can use the directory traversal to locate and manipulate critical system files or services.
Mitigation strategies for CVE-2003-1349 should focus on immediate patching and configuration hardening to prevent exploitation of this directory traversal vulnerability. The most effective approach is to upgrade to a patched version of the NITE ftp-server software that properly validates and sanitizes input paths in the CWD command. Organizations should implement proper input validation that rejects or normalizes path components containing backslash dot dot sequences before processing them within the FTP service. Network segmentation and firewall rules should be implemented to restrict access to FTP services to only authorized clients, reducing the attack surface. The server configuration should enforce strict directory boundaries and prevent access to parent directories through relative path references. Additional security measures include implementing intrusion detection systems that can monitor for suspicious CWD commands containing path traversal sequences, and conducting regular security audits of FTP server configurations. Access controls should be tightened to ensure that FTP users have minimal necessary privileges, and logging should be enabled to track directory access attempts. The implementation of proper path normalization routines that resolve and validate all path components before processing can prevent similar vulnerabilities in other FTP implementations. Security professionals should also consider implementing application-level firewalls or proxies that can filter out suspicious path traversal attempts before they reach the FTP server. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar path traversal vulnerabilities in other system components. Organizations should also establish incident response procedures specifically addressing FTP service vulnerabilities to ensure rapid response to potential exploitation attempts.