CVE-2001-0697 in SurgeFTP
Summary
by MITRE
NetWin SurgeFTP prior to 1.1h allows a remote attacker to cause a denial of service (crash) via an ls .. command.
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Analysis
by VulDB Data Team • 10/05/2025
The vulnerability identified as CVE-2001-0697 affects NetWin SurgeFTP versions prior to 11h, presenting a significant denial of service risk that can be exploited remotely by malicious actors. This flaw specifically manifests when a remote attacker sends an ls .. command to the affected FTP server, causing the service to crash and become unavailable to legitimate users. The vulnerability represents a classic buffer overflow or improper input validation issue that has been documented in the context of FTP server implementations since the early days of network security. The impact of this vulnerability extends beyond simple service disruption as it can be leveraged by attackers to maintain persistent availability issues against critical network infrastructure.
The technical nature of this vulnerability stems from inadequate handling of directory traversal commands within the FTP protocol implementation. When the ls .. command is processed, the application fails to properly validate or sanitize the input parameters, leading to a condition where the server crashes or becomes unresponsive. This type of flaw typically falls under CWE-121, which encompasses buffer overflow conditions, or CWE-122, which addresses buffer overflow vulnerabilities that can be exploited for denial of service attacks. The vulnerability operates at the application layer of the network stack and requires minimal privileges to exploit, making it particularly dangerous for systems that rely on FTP services for file transfer operations. The attack vector is straightforward and can be executed through any standard FTP client that supports the ls command, making it accessible to attackers with basic networking knowledge.
From an operational perspective, this vulnerability creates substantial risk for organizations that depend on FTP services for business operations. The remote exploitation capability means that attackers can trigger the denial of service condition from anywhere on the network, potentially causing widespread disruption to file sharing and data transfer activities. The crash condition can result in complete service unavailability until manual intervention or system restart occurs, leading to potential business interruption and data accessibility issues. Organizations may experience cascading effects if the FTP service is used for critical operations such as software distribution, backup transfers, or automated file processing systems. The vulnerability also represents a potential entry point for more sophisticated attacks, as service disruption can be used as a precursor to other exploitation techniques, aligning with ATT&CK tactic TA0040 (execution) and technique T1499.004 (network denial of service).
Mitigation strategies for CVE-2001-0697 should focus on immediate patching of affected systems to upgrade to NetWin SurgeFTP version 1.1h or later, which contains the necessary fixes for proper input validation. System administrators should implement network segmentation and access controls to limit exposure of FTP services to only authorized users and networks. Additional protective measures include implementing intrusion detection systems that can monitor for suspicious FTP command patterns and configuring firewalls to restrict FTP service access. Regular security assessments and vulnerability scanning should be conducted to identify other potentially vulnerable services within the network infrastructure. The remediation process should also include monitoring for any signs of exploitation attempts and maintaining detailed logs of FTP service activities for forensic analysis purposes. Organizations should consider migrating away from legacy FTP implementations toward more secure alternatives such as SFTP or FTPS to reduce the attack surface and improve overall security posture.