CVE-2025-5667 is a buffer overflow vulnerability identified in FreeFloat FTP Server version 1.0, specifically within the REIN Command Handler component. Buffer overflow vulnerabilities occur when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory. This can lead to arbitrary code execution, crashes, or other unpredictable behavior. The vulnerability is exploitable remotely without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The attack surface involves the FTP server's handling of the REIN command, which is used to reinitialize the connection. Improper input validation or bounds checking in this command handler allows an attacker to send crafted requests that overflow the buffer. While the CVSS score is 6.9 (medium severity), the vulnerability's characteristics—remote exploitation, no privileges required, and no user interaction—make it a significant risk. The CVSS vector also notes low impact on confidentiality, integrity, and availability, suggesting that while exploitation is feasible, the consequences may be limited or require additional conditions for full compromise. No patches or mitigations have been publicly linked yet, and no known exploits are reported in the wild, but the public disclosure increases the risk of exploitation attempts. Organizations running FreeFloat FTP Server 1.0 should consider this vulnerability critical to address promptly due to the potential for remote code execution or denial of service through buffer overflow exploitation.

For European organizations, this vulnerability poses a risk primarily to those using FreeFloat FTP Server 1.0 for file transfer services. Exploitation could lead to unauthorized remote code execution or service disruption, impacting business continuity and data integrity. FTP servers often handle sensitive data transfers; thus, a compromise could expose confidential information or allow attackers to pivot within networks. The medium CVSS score suggests limited direct impact on confidentiality and integrity, but the ease of remote exploitation without authentication elevates the threat level. Critical infrastructure, financial institutions, and enterprises relying on FTP for internal or external data exchange could face operational disruptions or data breaches. Additionally, regulatory requirements under GDPR mandate prompt remediation of vulnerabilities to protect personal data, increasing the compliance risk for affected entities. The lack of available patches means organizations must implement interim controls to mitigate exposure. The public disclosure also increases the likelihood of targeted attacks against European organizations, especially those with exposed FTP services.

1. Immediate mitigation should include disabling or restricting access to FreeFloat FTP Server 1.0 instances until a patch is available. 2. Implement network-level controls such as firewall rules to limit FTP access to trusted IP addresses only. 3. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection to identify and block exploitation attempts targeting the REIN command. 4. Monitor FTP server logs for unusual or malformed REIN command requests indicative of exploitation attempts. 5. Where possible, replace FreeFloat FTP Server 1.0 with a more secure, actively maintained FTP solution that has no known vulnerabilities. 6. Apply network segmentation to isolate FTP servers from critical systems to reduce lateral movement risk. 7. Educate IT staff on the vulnerability and ensure incident response plans include steps for potential exploitation scenarios. 8. Regularly review and update firewall and access control policies to minimize exposure of FTP services to the internet. 9. If patching becomes available, prioritize immediate deployment after testing in controlled environments.