CVE-2001-0680 in NET
Summary
by MITRE
Directory traversal vulnerability in ftpd in QPC QVT/Net 4.0 and AVT/Term 5.0 allows a remote attacker to traverse directories on the web server via a "dot dot" attack in a LIST (ls) command.
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Analysis
by VulDB Data Team • 05/11/2019
The vulnerability identified as CVE-2001-0680 represents a critical directory traversal flaw within the ftpd component of QPC QVT/Net 4.0 and AVT/Term 5.0 software products. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data during the processing of LIST commands. The vulnerability specifically affects the FTP server implementation where the system does not adequately restrict path resolution when handling dot-dot sequences in file listing requests. Attackers can exploit this weakness by crafting malicious LIST commands containing directory traversal sequences such as "../" or "..\\" to navigate outside the intended directory structure and access restricted files or directories on the web server.
The technical exploitation of this vulnerability occurs at the protocol level where the FTP server processes LIST commands without proper validation of the requested paths. When a malicious user submits a LIST command with traversal sequences, the server fails to normalize or validate the path components, allowing the attacker to access files outside the designated web root or FTP directory boundaries. This flaw directly maps to CWE-22, which defines improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability demonstrates a fundamental lack of input sanitization and path validation within the FTP server's command processing pipeline, creating an attack surface that enables unauthorized file access and potential data exfiltration.
Operationally, this vulnerability poses significant risks to web server security and data integrity. Remote attackers can leverage this weakness to access sensitive files including configuration files, database files, system logs, and potentially administrative credentials stored outside the intended web server directories. The impact extends beyond simple file access as attackers may be able to discover system structure, identify running services, and gather intelligence for further exploitation. The vulnerability is particularly dangerous in environments where FTP services are exposed to untrusted networks or where the web server shares directories with sensitive system files. According to ATT&CK framework, this vulnerability aligns with T1083 (File and Directory Discovery) and T1566 (Phishing) as attackers can use directory traversal to gather information about the target system and potentially escalate privileges through access to system configuration files.
Mitigation strategies for CVE-2001-0680 should focus on implementing proper input validation and path normalization within the FTP server implementation. System administrators should immediately apply vendor patches or updates that address the directory traversal vulnerability in QPC QVT/Net and AVT/Term software components. Additionally, network segmentation should be implemented to limit access to FTP services, and firewall rules should restrict FTP access to trusted IP addresses only. The implementation of secure coding practices including proper path validation, canonicalization of file paths, and enforcement of strict directory access controls can prevent similar vulnerabilities from occurring in the future. Organizations should also consider implementing intrusion detection systems to monitor for suspicious LIST command patterns and establish regular security assessments to identify and remediate similar path traversal vulnerabilities across their infrastructure.