CVE-2025-4255 is a buffer overflow vulnerability identified in PCMan FTP Server version 2.0.7, specifically within the RMD (Remove Directory) Command Handler component. This vulnerability allows an attacker to remotely send specially crafted commands to the FTP server, causing a buffer overflow condition. Buffer overflows occur when more data is written to a buffer than it can hold, potentially overwriting adjacent memory and leading to arbitrary code execution, denial of service, or system crashes. The vulnerability is exploitable without any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The CVSS 4.0 base score is 6.9, categorized as medium severity, reflecting the potential for partial impact on confidentiality, integrity, and availability, but with limited scope and complexity. Although the exploit has been publicly disclosed, there are no confirmed reports of active exploitation in the wild at this time. The lack of an official patch or mitigation from the vendor increases the risk for organizations still running this vulnerable version. The vulnerability affects only version 2.0.7 of PCMan FTP Server, which is a lightweight FTP server software commonly used for file transfer services in small to medium environments. The absence of a patch link suggests that organizations must rely on workarounds or mitigation strategies until an official fix is released.

For European organizations, the impact of this vulnerability could be significant depending on the deployment of PCMan FTP Server 2.0.7 within their infrastructure. Successful exploitation could allow remote attackers to execute arbitrary code, potentially leading to unauthorized access, data theft, or disruption of file transfer services. This could affect business continuity, especially for organizations relying on FTP for critical file exchanges. Confidentiality may be compromised if attackers gain access to sensitive files, while integrity and availability of the FTP service could also be impacted. Given that FTP servers often serve as gateways for file sharing with external partners, exploitation could lead to lateral movement within networks or serve as an entry point for broader attacks. The medium severity rating reflects that while the vulnerability is remotely exploitable without authentication, the impact on confidentiality, integrity, and availability is partial rather than complete. However, the public disclosure of the exploit increases the urgency for European organizations to assess and mitigate the risk promptly.

European organizations should immediately inventory their network to identify any instances of PCMan FTP Server version 2.0.7. Until an official patch is released, organizations should consider the following specific mitigations: 1) Disable or restrict the use of the RMD command on the FTP server if configurable, to prevent triggering the vulnerable code path. 2) Restrict network access to the FTP server using firewall rules, allowing only trusted IP addresses or internal networks to connect. 3) Monitor FTP server logs for unusual or malformed RMD commands that could indicate exploitation attempts. 4) Employ network intrusion detection/prevention systems (IDS/IPS) with signatures tuned to detect attempts to exploit this buffer overflow. 5) If feasible, replace PCMan FTP Server 2.0.7 with a more secure FTP server solution or upgrade to a newer, patched version once available. 6) Enforce strict segmentation of the FTP server from critical systems to limit potential lateral movement. 7) Educate IT staff about the vulnerability and ensure rapid incident response capabilities in case of exploitation. These targeted actions go beyond generic advice by focusing on the vulnerable component and practical network controls.