CVE-2001-1300 in FTP Server
Summary
by MITRE
Directory traversal vulnerability in Dynu FTP server 1.05 and earlier allows remote attackers to read arbitrary files via a .. in the CD (CWD) command.
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Analysis
by VulDB Data Team • 03/24/2017
The vulnerability identified as CVE-2001-1300 represents a critical directory traversal flaw affecting Dynu FTP server versions 1.05 and earlier. This security weakness resides in the server's handling of the CD (CWD) command, which is used to change directories within the file system. The flaw allows remote attackers to manipulate the directory navigation functionality by injecting dot-dot sequences into the CWD command, thereby enabling unauthorized access to files outside the intended directory structure. The vulnerability specifically exploits the lack of proper input validation and path sanitization within the FTP server's directory change implementation.
The technical implementation of this vulnerability stems from insufficient boundary checking and path normalization within the Dynu FTP server's command processing logic. When a client sends a CWD command containing .. sequences, the server fails to properly resolve these references through the file system's directory traversal mechanisms. This allows attackers to navigate upward through directory hierarchies and access files that should remain restricted to authorized users. The vulnerability is classified as a directory traversal attack pattern, aligning with CWE-22 which describes improper limitation of a pathname to a restricted directory. The flaw essentially permits an attacker to bypass normal file system access controls by manipulating the directory change command.
From an operational perspective, this vulnerability poses significant risks to organizations relying on vulnerable Dynu FTP server implementations. Remote attackers can exploit this weakness to access sensitive configuration files, user credentials, application data, and system files that may contain critical information. The impact extends beyond simple file reading, as attackers could potentially access database files, application source code, or system configuration details that could facilitate further exploitation. This vulnerability enables attackers to perform reconnaissance activities and gather intelligence about the target system, potentially leading to more severe compromises. The remote nature of the attack means that exploitation does not require physical access or local system privileges, making it particularly dangerous for networked environments.
Mitigation strategies for this vulnerability focus on immediate remediation through software updates and patches provided by the vendor. Organizations should prioritize upgrading to Dynu FTP server versions that have addressed this directory traversal flaw. Additionally, network-level controls such as firewall rules can be implemented to restrict FTP access to trusted networks and limit the exposure of vulnerable systems. Input validation measures should be enforced at the application level to sanitize all user-supplied data, particularly commands that manipulate directory paths. Security monitoring should include detection of suspicious CWD command sequences containing .. patterns, which could indicate attempted exploitation. The implementation of principle of least privilege access controls and regular security audits of FTP server configurations can further reduce the risk of successful exploitation. This vulnerability also highlights the importance of following secure coding practices and conducting thorough security testing of network services, particularly those handling user input. Organizations should consider implementing network segmentation to isolate FTP services and reduce the potential impact of such vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under privilege escalation and credential access techniques, emphasizing the need for comprehensive security measures beyond simple patch management to protect against sophisticated attack vectors.