CVE-2000-0523 in EServ
Summary
by MITRE
Buffer overflow in the logging feature of EServ 2.9.2 and earlier allows an attacker to execute arbitrary commands via a long MKD command.
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Analysis
by VulDB Data Team • 10/14/2025
The vulnerability identified as CVE-2000-0523 represents a critical buffer overflow flaw within the logging functionality of EServ 2.9.2 and earlier versions of the EServ web server software. This issue specifically manifests when processing the MKD (Make Directory) command, which is part of the File Transfer Protocol (FTP) protocol used for directory creation operations. The buffer overflow occurs because the application fails to properly validate the length of input data provided in the MKD command, allowing an attacker to supply excessive data that overflows the allocated buffer space. This particular vulnerability falls under the CWE-121 buffer overflow category, which is classified as a critical weakness in software design that enables attackers to overwrite adjacent memory locations.
The technical exploitation of this vulnerability requires an attacker to send a specially crafted MKD command containing more data than the buffer can accommodate. When the server processes this malformed command, the excess data overflows into adjacent memory regions, potentially overwriting critical program variables, return addresses, or function pointers. This memory corruption can be leveraged to redirect program execution flow, enabling the attacker to inject and execute arbitrary code with the privileges of the affected service. The vulnerability is particularly dangerous because it allows remote code execution without requiring authentication, making it a severe threat to systems running vulnerable versions of EServ. The attack vector operates entirely through the standard FTP protocol, making it accessible to any attacker with network connectivity to the target system.
The operational impact of CVE-2000-0523 extends beyond simple remote code execution, as it can lead to complete system compromise and unauthorized access to sensitive data. Organizations running vulnerable EServ instances face significant risks including data breaches, system takeover, and potential lateral movement within their network infrastructure. The vulnerability affects systems where EServ is configured to handle FTP requests, particularly those exposed to untrusted networks or internet-facing servers. This issue aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as attackers can execute arbitrary commands through the compromised server. The vulnerability also maps to T1078 legitimate credentials, as successful exploitation may provide attackers with persistent access to the compromised system.
Mitigation strategies for this vulnerability require immediate patching of affected EServ installations to version 2.9.3 or later, which contains the necessary fixes to prevent buffer overflow conditions. System administrators should implement network segmentation to limit access to FTP services and consider disabling unnecessary FTP functionality where possible. Additional protective measures include implementing firewall rules to restrict FTP access to trusted networks, deploying intrusion detection systems to monitor for suspicious MKD command patterns, and conducting regular security assessments to identify other potential buffer overflow vulnerabilities in legacy software. Organizations should also consider migrating away from unsupported software versions to maintain security posture and ensure ongoing vendor support for security updates. The vulnerability demonstrates the critical importance of proper input validation and memory management practices in server software development, emphasizing the need for robust security testing throughout the software development lifecycle.