CVE-2025-5634 is a buffer overflow vulnerability identified in PCMan FTP Server version 2.0.7, specifically within the NOOP command handler component. The NOOP command in FTP is typically used to keep the connection alive without performing any action. However, in this case, improper handling of the NOOP command input leads to a buffer overflow condition. This vulnerability can be exploited remotely without any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The buffer overflow could allow an attacker to overwrite memory, potentially leading to arbitrary code execution, denial of service, or system crashes. Although the CVSS score is 6.9 (medium severity), the exploitability is high due to the lack of required privileges and user interaction. The vulnerability affects only version 2.0.7 of PCMan FTP Server, and no patches or fixes have been disclosed yet. No known exploits are reported in the wild at the time of publication, but public disclosure of the exploit code increases the risk of exploitation. The vulnerability does not require special conditions such as user authentication or complex attack vectors, making it a significant threat to exposed FTP servers running this specific version. The absence of scope change (S:U) means the impact is limited to the vulnerable component or system, but the potential for remote code execution elevates the risk profile.

For European organizations, this vulnerability poses a notable risk, especially for those relying on PCMan FTP Server 2.0.7 for file transfer services. Exploitation could lead to unauthorized remote code execution, allowing attackers to compromise the confidentiality, integrity, and availability of affected systems. This could result in data breaches, service disruptions, or use of compromised servers as footholds for further network intrusion. Given the FTP server's role in handling sensitive file transfers, exploitation could expose critical business data or intellectual property. The medium CVSS score might underestimate the real-world impact because the exploit requires no authentication and can be launched remotely. Organizations with legacy or unpatched FTP infrastructure are particularly vulnerable. Additionally, the lack of patches means organizations must rely on alternative mitigations until a fix is released. The threat is exacerbated by the public availability of exploit code, increasing the likelihood of opportunistic attacks. European entities in sectors such as finance, manufacturing, and government, which often use FTP for legacy systems or inter-organizational file exchanges, could face operational and reputational damage if exploited.

Immediate mitigation should focus on reducing the attack surface by disabling or restricting access to PCMan FTP Server 2.0.7 instances, especially from untrusted networks. Network-level controls such as firewall rules should block incoming FTP traffic unless absolutely necessary. Where FTP is required, consider isolating the server in a segmented network zone with strict access controls. Monitoring and logging FTP server activity can help detect anomalous NOOP command usage indicative of exploitation attempts. Organizations should plan to upgrade to a patched version once available or migrate to more secure file transfer solutions supporting encrypted protocols like SFTP or FTPS. In the interim, applying intrusion prevention system (IPS) signatures that detect malformed NOOP commands or buffer overflow attempts can provide additional protection. Regular vulnerability scanning and asset inventory to identify affected servers are critical. Additionally, educating IT staff about this vulnerability and ensuring incident response plans include scenarios involving FTP server compromise will improve preparedness.