CVE-2004-0437 in Titan FTP Server
Summary
by MITRE
Titan FTP Server version 3.01 build 163, and possibly other versions before build 169, allows remote authenticated users to cause a denial of service (crash) by disconnecting from the system during a "LIST -L" command, which causes Titan to access an invalid socket.
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Analysis
by VulDB Data Team • 08/17/2025
The vulnerability identified as CVE-2004-0437 affects Titan FTP Server version 3.01 build 163 and potentially earlier versions up to build 168. This issue represents a classic denial of service condition that exploits a race condition or improper resource management during specific FTP command processing. The vulnerability specifically manifests when authenticated users disconnect from the server while the system is processing a "LIST -L" command, which is a standard FTP command used to retrieve directory listings with detailed information. The flaw stems from the server's inadequate handling of socket connections during the execution of this particular command sequence.
The technical root cause of this vulnerability lies in the improper management of socket resources within the Titan FTP Server implementation. When a user disconnects during the execution of a "LIST -L" command, the server attempts to access a socket that has already been closed or invalidated by the disconnection event. This creates a scenario where the server's internal state becomes inconsistent, leading to memory access violations or null pointer dereferences that ultimately result in the application crashing. The vulnerability is classified as a resource management error and aligns with CWE-476 which addresses NULL pointer dereference issues. The improper handling of connection states during command execution demonstrates a lack of proper error checking and resource cleanup mechanisms.
The operational impact of this vulnerability extends beyond simple service disruption as it provides a method for authenticated attackers to systematically destabilize the FTP server. While the vulnerability requires authentication to exploit, it represents a significant security concern because it allows attackers with valid credentials to cause persistent service interruptions. The denial of service condition can be repeated multiple times, potentially leading to extended periods of service unavailability that could impact legitimate users and business operations. This vulnerability also demonstrates poor defensive programming practices that could indicate additional weaknesses in the server's overall security posture and resource management capabilities.
Mitigation strategies for this vulnerability primarily involve upgrading to Titan FTP Server build 169 or later, which contains the necessary patches to properly handle socket disconnections during command processing. System administrators should also implement proper monitoring and alerting mechanisms to detect unusual service disruptions that might indicate exploitation attempts. Network-level protections such as connection rate limiting and automated service restart procedures can provide additional defense-in-depth measures. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving service disruption and resource exhaustion, and represents a potential entry point for more sophisticated attacks that could leverage the service disruption as a means to gain further access or cause additional damage through cascading failures in dependent systems.