CVE-2002-1920 in FtpXQ
Summary
by MITRE
Buffer overflow in FtpXQ 2.5 allows remote attackers to cause a denial of service (crash) via a MKD command with a long directory name.
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Analysis
by VulDB Data Team • 09/01/2025
The vulnerability identified as CVE-2002-1920 represents a classic buffer overflow flaw within the FtpXQ 2.5 file transfer protocol implementation that specifically affects the MKD command functionality. This issue arises from inadequate input validation and boundary checking mechanisms within the FTP server software, creating a condition where maliciously crafted directory names can exceed the allocated buffer space. The vulnerability operates at the application layer of the network stack, targeting the core FTP protocol handling mechanisms that process directory creation requests from remote clients.
The technical exploitation of this buffer overflow occurs when a remote attacker sends an MKD command containing an excessively long directory name that surpasses the predetermined buffer size allocated for handling such requests. When the FTP server processes this malformed input without proper bounds checking, the excess data overflows into adjacent memory regions, potentially corrupting critical program state information and ultimately causing the application to crash or terminate unexpectedly. This type of vulnerability falls under CWE-121, which categorizes buffer overflow conditions that occur when insufficient space is allocated for data, and specifically aligns with the ATT&CK technique T1499.004 for network denial of service attacks.
The operational impact of this vulnerability extends beyond simple service disruption to potentially create a persistent availability threat within networked environments that rely on FTP services for file management operations. Organizations utilizing FtpXQ 2.5 systems face significant risk of unauthorized denial of service attacks that can render critical file transfer services unavailable to legitimate users, potentially disrupting business operations and data management workflows. The vulnerability demonstrates how seemingly benign protocol commands can become attack vectors when proper input sanitization is absent, highlighting the importance of defensive programming practices in network service implementations.
Mitigation strategies for this vulnerability should prioritize immediate patching of the FtpXQ 2.5 software to address the buffer overflow condition through proper input validation and boundary checking mechanisms. Network administrators should implement additional protective measures including firewall rules that limit FTP service exposure, rate limiting to prevent abuse of the MKD command, and monitoring systems that can detect anomalous directory creation patterns. The remediation process should also involve comprehensive code review to ensure similar buffer overflow conditions do not exist in other command handlers within the FTP service implementation, following industry best practices for secure coding standards and input validation as recommended by the OWASP Secure Coding Practices. Organizations should also consider implementing intrusion detection systems that can identify and alert on potential exploitation attempts targeting this specific vulnerability pattern.