CVE-2016-15060 in FTP Server
Summary
by MITRE • 10/14/2026
A vulnerability was found in PCMan FTP Server up to 2.0.7. This affects an unknown function of the component PORT Command Handler. The manipulation results in buffer overflow. The attack can be launched remotely. The exploit has been made public and could be used.
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Analysis
by VulDB Data Team • 10/14/2026
The discovery of a critical vulnerability within PCMan FTP Server versions up to 2.0.7 highlights significant security deficiencies in legacy file transfer applications that remain prevalent in many enterprise environments. This specific flaw resides within the PORT command handler, a core component responsible for managing data connections initiated by clients requesting active mode transfers. The vulnerability is classified as a buffer overflow, specifically categorized under CWE-120: Buffer Copy without Checking Size of Input. In this context, the application fails to adequately validate or bound-check input data provided via the PORT command before copying it into a fixed-size stack-based buffer. This lack of rigorous boundary checking allows an attacker to supply oversized or malformed input that exceeds the allocated memory space, leading to adjacent memory corruption and potential control flow hijacking.
The operational impact of this vulnerability is severe due to its remote exploitable nature. An unauthenticated attacker can connect to the FTP service on port 21 and craft a malicious PORT command containing specially crafted data designed to overflow the buffer in the handler function. Because PCMan FTP Server often runs with elevated privileges or as part of critical file sharing infrastructure, successful exploitation could allow an attacker to execute arbitrary code on the affected system. This aligns closely with MITRE ATT&CK technique T1059: Command and Scripting Interpreter, where attackers leverage compromised systems to run malicious commands. The public availability of exploit code significantly lowers the barrier for entry, enabling less sophisticated threat actors to compromise vulnerable servers without needing advanced reverse engineering skills or custom tool development.
From a technical perspective, buffer overflows in network-facing services are particularly dangerous because they provide direct pathways to remote code execution (RCE). When the stack-based buffer is overwritten, an attacker can manipulate return addresses or function pointers within the program's control flow. This manipulation enables the injection and execution of shellcode, effectively granting the attacker full administrative access to the underlying operating system. The persistence of such vulnerabilities in software versions as recent as 2.0.7 suggests a lack of secure coding practices during development, particularly regarding input validation and memory management safety checks that are standard requirements in modern cybersecurity frameworks like OWASP Top Ten for API Security and Web Application Testing.
Mitigation strategies must prioritize immediate remediation through vendor updates if available, although given the age of PCMan FTP Server, official patches may no longer be provided by the original developers. In such cases, organizations should consider replacing the vulnerable software with a modern, actively maintained alternative that adheres to current security standards. If migration is not immediately feasible, network-level controls become essential. Implementing strict firewall rules to restrict access to port 21 only from trusted IP addresses can reduce the attack surface significantly. Additionally, deploying intrusion detection systems configured to detect anomalous FTP traffic patterns associated with buffer overflow attempts can provide an additional layer of defense. Regular vulnerability scanning and penetration testing should be conducted to identify other potential weaknesses in legacy infrastructure that may pose similar risks to organizational security posture.