CVE-2000-0131 in WarFTPd
Summary
by MITRE
Buffer overflow in War FTPd 1.6x allows users to cause a denial of service via long MKD and CWD commands.
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Analysis
by VulDB Data Team • 10/19/2025
The vulnerability identified as CVE-2000-0131 represents a critical buffer overflow flaw within War FTPd version 1.6x that specifically affects the handling of MKD and CWD commands. This issue stems from inadequate input validation and bounds checking within the file transfer protocol implementation, creating a pathway for malicious actors to exploit the service through carefully crafted command sequences. The vulnerability manifests when users submit excessively long arguments to the MKD (Make Directory) and CWD (Change Working Directory) commands, which are fundamental operations in ftp protocol interactions.
The technical implementation of this buffer overflow occurs due to the software's failure to properly validate the length of user-supplied input data before processing it within fixed-size memory buffers. When an attacker sends a command containing more characters than the allocated buffer space can accommodate, the excess data overflows into adjacent memory regions, potentially corrupting critical program state information or even executing arbitrary code. This particular implementation flaw aligns with CWE-121, which categorizes stack-based buffer overflow conditions, and demonstrates how insufficient bounds checking can lead to complete system compromise. The attack vector specifically targets the ftp daemon's command processing routines where directory creation and navigation operations are handled, making it particularly dangerous as it can be exploited by any authenticated or unauthenticated user depending on the server configuration.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enable more severe compromise scenarios. While the immediate effect may appear as a service disruption, the underlying buffer overflow creates opportunities for privilege escalation and persistent system compromise. An attacker could leverage this vulnerability to cause the ftp daemon to crash repeatedly, leading to denial of service for legitimate users, or potentially execute malicious code with the privileges of the ftp service account. The implications are particularly concerning in environments where ftp services are used for critical file transfers or as part of larger network infrastructure components. This vulnerability also demonstrates how legacy software implementations often lack modern security protections such as stack canaries, address space layout randomization, or other exploit mitigation techniques that would make such attacks significantly more difficult to execute successfully.
Mitigation strategies for CVE-2000-0131 should focus on immediate patching of the affected War FTPd version, as the vendor has released updates addressing the buffer overflow conditions. Organizations should implement network segmentation to limit access to ftp services and employ intrusion detection systems that can identify suspicious command sequences targeting this specific vulnerability. The implementation of input validation controls at network boundaries and within ftp service configurations can provide additional layers of protection. Security practitioners should also consider deploying application firewalls or web application firewalls that can filter out malformed commands before they reach the vulnerable service. From an ATT&CK perspective, this vulnerability maps to technique T1210 - Exploitation of Remote Services and T1499 - Endpoint Termination, as it represents both a service exploitation vector and a potential means for system termination or compromise. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other legacy ftp implementations that may share similar buffer overflow characteristics, as this represents a common class of vulnerability in older network service implementations that were not designed with modern security considerations in mind.