CVE-2006-6643 in Star FTP server
Summary
by MITRE
Fightersoft Multimedia Star FTP server 1.10 allows remote attackers to cause a denial of service (crash) via multiple RETR commands with long arguments.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/21/2024
The Fightersoft Multimedia Star FTP server version 1.10 contains a critical vulnerability that enables remote attackers to execute a denial of service attack through carefully crafted RETR commands. This vulnerability stems from insufficient input validation and memory management within the server's handling of file retrieval requests, specifically when processing multiple RETR commands with excessively long argument strings. The flaw represents a classic buffer overflow condition that occurs when the server fails to properly sanitize user inputs before processing them, leading to memory corruption and subsequent system crash.
The technical implementation of this vulnerability involves the FTP server's response to the RETR command which is used to retrieve files from the server. When an attacker sends multiple RETR commands with arguments that exceed the server's expected parameter length, the server's internal buffer handling mechanisms become overwhelmed. This occurs because the server does not implement proper bounds checking or input length validation for the file path arguments provided in RETR commands. The excessive argument lengths cause memory allocation issues within the server's processing loop, ultimately resulting in a segmentation fault or memory corruption that terminates the FTP service.
From an operational impact perspective, this vulnerability creates significant risk for organizations relying on the Fightersoft Multimedia Star FTP server for file transfer operations. The denial of service condition effectively renders the FTP service unavailable to legitimate users, potentially disrupting business operations and data access. The attack requires minimal sophistication and can be executed remotely without authentication, making it particularly dangerous in production environments. Network administrators may experience service interruptions that could affect critical file sharing operations, backup processes, or data synchronization activities depending on the server's role within the organization's infrastructure.
The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and represents a variant of the broader category of input validation flaws that frequently appear in network service implementations. From an attacker's perspective, this vulnerability maps to ATT&CK technique T1499.004, which covers network denial of service attacks, and T1595.001, covering reconnaissance through network scanning and service discovery. The attack vector specifically targets the server's file transfer protocol implementation, making it a prime candidate for exploitation in automated attack frameworks. Organizations should consider implementing network segmentation, firewall rules to restrict FTP service access, and regular patching procedures to prevent exploitation of this vulnerability.
Mitigation strategies should include immediate deployment of vendor patches if available, implementing input length restrictions on FTP commands, and configuring network access controls to limit exposure to trusted networks only. System administrators should also establish monitoring procedures to detect unusual patterns of RETR command usage that might indicate attempted exploitation. Additionally, organizations should consider migrating to more robust FTP server implementations that have undergone thorough security testing and maintain active support for security updates. The vulnerability highlights the importance of proper input validation and memory management in network service applications, serving as a reminder that even seemingly simple protocol implementations can contain critical security flaws that require careful attention to prevent exploitation.