CVE-2000-0875 in wftpd
Summary
by MITRE
WFTPD and WFTPD Pro 2.41 RC12 allows remote attackers to cause a denial of service by sending a long string of unprintable characters.
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Analysis
by VulDB Data Team • 05/18/2019
The vulnerability identified as CVE-2000-0875 affects WFTPD and WFTPD Pro version 2.41 RC12, representing a classic buffer overflow condition that manifests through improper input validation. This flaw exists within the file transfer protocol implementation where the software fails to adequately sanitize incoming data streams, particularly when processing user credentials or directory names. The vulnerability stems from the application's inability to handle extended character sequences that exceed predetermined buffer limits, creating a condition where malicious actors can exploit this weakness to disrupt service availability. The flaw is categorized under CWE-121 as a stack-based buffer overflow, which occurs when data is written beyond the boundaries of allocated memory regions. This particular implementation issue demonstrates poor defensive programming practices where input validation mechanisms are insufficient to prevent exploitation through malformed data sequences.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable broader system compromise within network environments. When remote attackers send specially crafted strings containing unprintable characters, the application crashes or becomes unresponsive, effectively creating a denial of service condition that prevents legitimate users from accessing file transfer services. The attack vector is particularly concerning as it requires minimal sophistication to execute, making it attractive to threat actors seeking to disrupt operations without significant technical expertise. This vulnerability aligns with ATT&CK technique T1499.004 which describes network denial of service attacks, and represents a fundamental weakness in protocol handling that could be leveraged as part of larger attack campaigns. The service disruption affects not only individual file transfer capabilities but can also impact business continuity and user productivity in environments where these services are critical.
Mitigation strategies for CVE-2000-0875 should prioritize immediate patching of affected systems to address the underlying buffer overflow condition. Organizations must implement input validation controls that enforce strict character set limitations and length restrictions on all user-supplied data, particularly in authentication and directory navigation contexts. Network segmentation and firewall rules can help limit exposure by restricting access to affected FTP services to trusted networks only. Additionally, implementing intrusion detection systems that monitor for unusual character sequences or connection patterns can provide early warning of potential exploitation attempts. The vulnerability highlights the importance of robust input sanitization and memory management practices that should be enforced throughout application development lifecycle processes. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other legacy applications that may be susceptible to analogous buffer overflow conditions. System administrators should also consider implementing automated monitoring and alerting mechanisms to quickly detect and respond to service disruptions that may indicate exploitation attempts.