CVE-2025-4791 is a critical buffer overflow vulnerability identified in FreeFloat FTP Server version 1.0, specifically within the HASH Command Handler component. This vulnerability arises due to improper handling of input data, which allows an attacker to manipulate the HASH command and cause a buffer overflow condition. Buffer overflows can lead to arbitrary code execution, denial of service, or system crashes. 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/PR:N). The CVSS score of 6.9 categorizes it as medium severity, reflecting the potential for partial impact on confidentiality, integrity, and availability, but with some limitations in scope or impact. The vulnerability affects only version 1.0 of the FreeFloat FTP Server, a product used to provide FTP services. Although no public exploits are currently known to be actively used in the wild, the exploit details have been disclosed, increasing the risk of exploitation by threat actors. The vulnerability does not require privileges or user interaction, making it easier to exploit remotely. The lack of a patch link suggests that a fix may not yet be available, emphasizing the need for immediate mitigation measures. The vulnerability’s impact vector includes limited confidentiality, integrity, and availability impacts, which may imply partial control or disruption rather than full system compromise. The vulnerability is classified as a remote code execution risk through buffer overflow, which is a common and dangerous class of vulnerabilities in network-facing services like FTP servers.

For European organizations, the presence of this vulnerability in FreeFloat FTP Server 1.0 could lead to unauthorized remote code execution or denial of service attacks, potentially disrupting critical file transfer operations. Organizations relying on this FTP server for internal or external data exchange could face data breaches, service outages, or system compromises. Given the remote and unauthenticated nature of the exploit, attackers could leverage this vulnerability to gain footholds in enterprise networks, escalate privileges, or move laterally. This is particularly concerning for sectors with high dependency on FTP for legacy systems or specialized applications, such as manufacturing, logistics, or government agencies. The medium severity rating suggests that while the impact is significant, it may not lead to full system takeover in all cases, but partial data exposure or service disruption is likely. The lack of known exploits in the wild currently reduces immediate risk but the public disclosure increases the likelihood of future exploitation attempts. European organizations with regulatory obligations under GDPR must also consider the risk of data breaches resulting from exploitation, which could lead to legal and financial penalties.

Given the absence of an official patch, European organizations should implement the following specific mitigations: 1) Immediately isolate or disable FreeFloat FTP Server 1.0 instances where feasible, especially those exposed to the internet. 2) Employ network-level controls such as firewall rules to restrict access to the FTP server only to trusted IP addresses and internal networks. 3) Monitor network traffic for unusual HASH command usage or anomalous FTP session behavior indicative of exploitation attempts. 4) Consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics targeting buffer overflow attempts against FTP services. 5) If FTP services are essential, evaluate migrating to alternative, actively maintained FTP server software that is not vulnerable. 6) Conduct thorough audits of systems running FreeFloat FTP Server to identify and remediate any signs of compromise. 7) Implement strict logging and alerting on FTP server activities to enable rapid incident response. 8) Educate IT and security teams about this vulnerability and ensure readiness to respond to exploitation attempts. 9) Engage with FreeFloat vendor or community for updates or patches and apply them promptly once available.