CVE-2002-2387 in Hyperion FTP Server
Summary
by MITRE
Directory traversal vulnerability in Hyperion FTP server 2.8.1 allows remote attackers to read arbitrary files via a .. (dot dot) in the LS command.
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Analysis
by VulDB Data Team • 04/20/2019
The vulnerability identified as CVE-2002-2387 represents a critical directory traversal flaw in the Hyperion FTP server version 2.8.1 that exposes systems to unauthorized file access. This weakness enables remote attackers to bypass normal file access controls and retrieve sensitive files from the server's file system through manipulation of the LIST command. The vulnerability specifically exploits the lack of proper input validation when processing the LS command, allowing malicious users to construct file paths containing directory traversal sequences that can navigate beyond the intended directory boundaries.
The technical implementation of this vulnerability stems from insufficient sanitization of user input within the FTP server's command processing logic. When the LS command receives a path parameter containing .. sequences, the server fails to properly validate or sanitize the input before executing file system operations. This allows attackers to craft malicious requests that traverse up directory trees and access files outside the designated FTP root directory. The flaw operates at the application layer and demonstrates a classic path traversal vulnerability pattern that has been documented in numerous security advisories over the years. According to CWE classification, this corresponds to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
The operational impact of CVE-2002-2387 extends beyond simple file access, as it can potentially lead to complete system compromise when combined with other vulnerabilities or attack vectors. An attacker exploiting this vulnerability could gain access to sensitive configuration files, user credentials stored in plaintext, system logs, and potentially even system binaries or database files. The remote nature of this attack means that no local system access is required, making it particularly dangerous for publicly accessible FTP servers. This vulnerability aligns with ATT&CK technique T1083 (File and Directory Discovery) and T1566 (Phishing) when used as part of broader reconnaissance or initial access phases in cyber operations.
Mitigation strategies for this vulnerability should prioritize immediate patching of the Hyperion FTP server to a version that properly validates and sanitizes input paths. Organizations should implement network segmentation to limit access to FTP services and consider disabling unnecessary FTP functionality where possible. Additional protective measures include implementing proper access controls, monitoring FTP server logs for suspicious directory traversal attempts, and deploying intrusion detection systems that can identify malformed LS command sequences. The vulnerability also highlights the importance of input validation practices and demonstrates why security controls should be implemented at multiple layers of the network infrastructure. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other network services that may be susceptible to path traversal attacks, as this remains a prevalent issue in legacy network applications and systems.