CVE-2000-1035 in FTP Server
Summary
by MITRE
Buffer overflows in TYPSoft FTP Server 0.78 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary commands via a long USER, PASS, or CWD command.
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Analysis
by VulDB Data Team • 03/16/2025
The vulnerability identified as CVE-2000-1035 represents a critical buffer overflow flaw within TYPSoft FTP Server version 0.78 and earlier implementations. This security weakness manifests when the server processes USER, PASS, or CWD commands that contain excessively long input strings, creating conditions where memory boundaries are exceeded. The vulnerability falls under the CWE-121 category of stack-based buffer overflow, where insufficient input validation allows attackers to overwrite adjacent memory locations. The flaw specifically targets the authentication and directory navigation functionalities of the FTP server, making it particularly dangerous for network administrators who rely on these services for file transfer operations.
The technical exploitation of this vulnerability occurs through carefully crafted malformed commands that exceed the allocated buffer space within the server's memory management. When an attacker sends a USER, PASS, or CWD command with input strings longer than the expected buffer capacity, the excess data overflows into adjacent memory regions, potentially corrupting critical program state information. This overflow can lead to unpredictable program behavior, including application crashes that result in denial of service conditions. In some cases, particularly when the overflow affects return addresses or function pointers, attackers may be able to manipulate the program execution flow to execute arbitrary code with the privileges of the affected service account. The vulnerability aligns with ATT&CK technique T1203 - Exploitation for Client Execution, as it leverages buffer overflow conditions to achieve remote code execution capabilities.
The operational impact of CVE-2000-1035 extends beyond simple service disruption to encompass potential system compromise and data exposure risks. Organizations running vulnerable FTP servers face significant threats including complete service outages that affect legitimate users and potential unauthorized access to sensitive files and system resources. The vulnerability's ability to cause denial of service means that critical business operations relying on file transfer capabilities could experience extended downtime. When combined with remote code execution capabilities, the flaw creates opportunities for attackers to establish persistent access, escalate privileges, and potentially move laterally within network environments. Network security teams must consider this vulnerability as part of broader FTP server hardening efforts, particularly in environments where legacy systems remain operational. The vulnerability demonstrates the importance of proper input validation and memory management practices in network services, as outlined in industry standards such as the OWASP Top Ten and NIST cybersecurity frameworks.
Mitigation strategies for CVE-2000-1035 require immediate attention through software updates and configuration hardening measures. Organizations should prioritize upgrading to TYPSoft FTP Server versions that address this vulnerability, as the original affected versions are no longer supported or maintained. Implementing input length restrictions on USER, PASS, and CWD commands serves as an effective temporary workaround while permanent fixes are deployed. Network segmentation and access control measures can limit the potential impact of exploitation attempts, while intrusion detection systems should be configured to monitor for suspicious command sequences. Security administrators should also consider implementing additional protective measures such as disabling unnecessary FTP server features, enforcing strong authentication mechanisms, and conducting regular vulnerability assessments to identify similar weaknesses in other network services. The remediation process should include thorough testing of updated software to ensure that security patches do not introduce compatibility issues with existing network infrastructure and business applications.