CVE-2000-0674 in FTP Browser
Summary
by MITRE
ftp.pl CGI program for Virtual Visions FTP browser allows remote attackers to read directories outside of the document root via a .. (dot dot) attack.
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Analysis
by VulDB Data Team • 05/05/2019
The vulnerability identified as CVE-2000-0674 affects the ftp.pl CGI program distributed with Virtual Visions FTP browser software, representing a classic directory traversal attack vector that has persisted as a fundamental web security flaw. This vulnerability specifically targets the improper handling of user-supplied input within the CGI script, allowing malicious actors to manipulate file path references through the use of directory traversal sequences. The flaw enables remote attackers to access files and directories beyond the intended document root boundaries, effectively bypassing access controls that should restrict file system access to authorized users only.
The technical implementation of this vulnerability stems from the ftp.pl CGI program's failure to properly sanitize or validate user input containing path traversal sequences such as "..". When the program processes requests containing these sequences, it does not adequately filter or normalize the input before using it in file system operations. This allows attackers to construct malicious paths that traverse upward through the directory structure, potentially accessing sensitive system files, configuration data, or other resources that should remain protected from unauthorized access. The vulnerability operates at the application layer and can be exploited through HTTP requests that include the problematic traversal sequences in parameters or path elements.
The operational impact of CVE-2000-0674 extends beyond simple information disclosure, as it provides attackers with the capability to access arbitrary files on the server filesystem. This can lead to exposure of sensitive data including configuration files containing database credentials, user authentication information, or system configuration details that could be leveraged for further exploitation. The vulnerability can result in complete system compromise when combined with other attack vectors, as it provides unauthorized access to the underlying file system that may contain critical system resources. Additionally, the vulnerability can be exploited to gain insights into the server's directory structure and potentially identify other vulnerable applications or services running on the same system.
Security practitioners should recognize this vulnerability as a variant of CWE-22, which specifically addresses Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal or Directory Traversal. The attack pattern aligns with ATT&CK technique T1083, which describes the discovery of system information through directory listing and file access operations. Mitigation strategies include implementing proper input validation and sanitization within the CGI application to reject or normalize traversal sequences, restricting file system access permissions for the web server process, and implementing proper path validation that ensures all file operations occur within designated safe directories. Organizations should also consider implementing web application firewalls to detect and block suspicious path traversal attempts, and conduct regular security assessments to identify and remediate similar vulnerabilities in other applications and services.