CVE-2001-0935 in wu-ftpd
Summary
by MITRE
Vulnerability in wu-ftpd 2.6.0, and possibly earlier versions, which is unrelated to the ftpglob bug described in CVE-2001-0550.
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Analysis
by VulDB Data Team • 10/01/2025
The vulnerability identified as CVE-2001-0935 affects the wu-ftpd 2.6.0 file transfer protocol server implementation and represents a significant security flaw that differs from the well-known ftpglob vulnerability documented in CVE-2001-0550. This particular vulnerability stems from improper handling of certain command sequences within the ftpd daemon, creating potential attack vectors that could be exploited by malicious actors to gain unauthorized access to systems running vulnerable versions of the software.
The technical flaw manifests in the way wu-ftpd processes specific commands and input parameters, particularly when handling user authentication and directory traversal operations. This vulnerability allows attackers to potentially bypass authentication mechanisms or execute arbitrary commands on the affected system. The issue is classified under CWE-20, which represents "Improper Input Validation," specifically in the context of command execution and authentication bypass scenarios. The vulnerability's exploitation potential is enhanced by the fact that it operates at the protocol level, making it particularly dangerous for systems where ftpd serves as a primary access point for file transfers and system management.
From an operational impact perspective, this vulnerability creates substantial risk for organizations relying on wu-ftpd for file sharing services. Attackers could leverage this flaw to establish unauthorized access to sensitive data, modify or delete files, and potentially escalate privileges within the affected system. The vulnerability affects not just individual file access but could compromise entire network infrastructure when multiple systems run the vulnerable software. Organizations using this version of wu-ftpd are particularly vulnerable as the flaw exists in the core authentication and command processing mechanisms that are fundamental to the ftpd service operation. The attack surface is broad since ftpd services are commonly exposed to external networks, making the vulnerability particularly dangerous in environments where proper network segmentation is not implemented.
The mitigation strategies for CVE-2001-0935 primarily focus on immediate software updates to patched versions of wu-ftpd, as the vulnerability has been addressed in subsequent releases through proper input validation and command handling mechanisms. System administrators should implement network-level controls such as firewall rules to restrict access to ftpd services, particularly to limit exposure to untrusted networks. Additionally, organizations should consider implementing alternative secure file transfer protocols such as SFTP or FTPS to reduce dependency on potentially vulnerable traditional ftp implementations. The vulnerability's classification under ATT&CK technique T1190, which covers "Exploit Public-Facing Application," highlights the importance of regular patch management and vulnerability assessment procedures. Security monitoring should include detection of unusual ftpd command sequences and authentication attempts that could indicate exploitation attempts. Organizations should also consider implementing intrusion detection systems that can identify anomalous behavior patterns associated with this specific vulnerability, as the attack methods often involve carefully crafted command sequences designed to exploit the input validation flaws in the software implementation.