CVE-2025-4254 is a buffer overflow vulnerability identified in PCMan FTP Server version 2.0.7, specifically within the LIST Command Handler component. The LIST command in FTP servers is used to retrieve directory listings, and improper handling of this command's input can lead to memory corruption. In this case, the vulnerability arises from insufficient bounds checking or improper input validation, allowing an attacker to send crafted LIST commands that overflow a buffer in the server's memory. This overflow can overwrite adjacent memory, potentially leading to arbitrary code execution, denial of service, or system instability. The vulnerability is remotely exploitable without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N). The CVSS 4.0 base score is 6.9, categorized as medium severity, reflecting that while the vulnerability is remotely exploitable and does not require privileges, the impact on confidentiality, integrity, and availability is limited to low levels individually. However, combined, these impacts can be significant. No public exploits are currently known in the wild, but the exploit details have been disclosed publicly, increasing the risk of exploitation. The lack of available patches at the time of disclosure increases the urgency for mitigation. Given the critical nature of FTP servers in file transfer and legacy system support, this vulnerability poses a tangible risk to organizations relying on PCMan FTP Server 2.0.7.

For European organizations, this vulnerability could lead to unauthorized remote code execution or denial of service on systems running the affected PCMan FTP Server version 2.0.7. This can compromise the confidentiality and integrity of sensitive data transferred via FTP, disrupt business operations dependent on FTP services, and potentially provide attackers with a foothold into internal networks. Organizations in sectors with stringent data protection requirements, such as finance, healthcare, and government, may face regulatory and reputational damage if exploited. Additionally, since FTP is often used in legacy environments, organizations with outdated infrastructure are at higher risk. The medium CVSS score suggests that while the vulnerability is serious, exploitation may not lead to full system compromise in all cases; however, the absence of authentication requirements and ease of remote exploitation elevate the threat level. European organizations with public-facing FTP servers or those that allow external connections to internal FTP services are particularly vulnerable. The public disclosure of the exploit details increases the likelihood of opportunistic attacks, especially targeting unpatched systems.

1. Immediate mitigation should include disabling the LIST command if feasible or restricting FTP server access to trusted IP addresses via firewall rules to reduce exposure. 2. Monitor network traffic for unusual or malformed FTP commands indicative of exploitation attempts. 3. Apply network-level intrusion detection/prevention systems (IDS/IPS) signatures targeting known exploit patterns for this vulnerability once available. 4. If patching is not yet available, consider migrating to alternative, actively maintained FTP server software with robust security controls. 5. Implement strict access controls and network segmentation to isolate FTP servers from critical infrastructure. 6. Conduct regular vulnerability scans and penetration tests focusing on FTP services to identify and remediate weaknesses. 7. Educate IT staff about this vulnerability and ensure incident response plans include scenarios involving FTP server compromise. 8. Once patches are released, prioritize their deployment in all affected environments to eliminate the vulnerability.