CVE-2025-5049 is a buffer overflow vulnerability identified in FreeFloat FTP Server version 1.0, specifically within the APPEND command handler component. Buffer overflow vulnerabilities occur when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory and leading to unpredictable behavior, including code execution or system crashes. This vulnerability can be exploited remotely without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The vulnerability affects the handling of the APPEND FTP command, which is used to append data to an existing file on the server. Improper validation or bounds checking in this command handler allows an attacker to send crafted requests that overflow the buffer, potentially leading to arbitrary code execution or denial of service. Although the CVSS base score is 6.9 (medium severity), the vulnerability is critical in nature due to the possibility of remote exploitation without privileges. The CVSS vector also indicates low complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N), which increases the risk of exploitation. However, the impact on confidentiality, integrity, and availability is rated as low to medium (VC:L, VI:L, VA:L), suggesting that while exploitation is possible, the extent of damage may be limited or require additional conditions. No patches or fixes have been linked yet, and no known exploits are reported in the wild at the time of publication. The disclosure date is May 21, 2025, and the vulnerability is publicly known, which could lead to increased attempts to exploit it.

For European organizations, this vulnerability poses a significant risk especially for those using FreeFloat FTP Server 1.0 in their infrastructure. FTP servers often handle sensitive file transfers, including confidential business data and personal information protected under GDPR. Exploitation could lead to unauthorized access, data corruption, or service disruption. Given the remote and unauthenticated nature of the attack, threat actors could leverage this vulnerability to gain foothold in networks, escalate privileges, or disrupt operations. Sectors such as finance, healthcare, manufacturing, and government agencies in Europe that rely on FTP for file exchange are particularly at risk. The potential for data breaches or operational downtime could result in regulatory penalties, reputational damage, and financial losses. Additionally, since no patches are currently available, organizations face a window of exposure until mitigations or updates are released. The medium CVSS score suggests moderate impact, but the ease of exploitation and unauthenticated access elevate the threat level for critical infrastructure and sensitive environments.

1. Immediate mitigation should include disabling or restricting access to the FreeFloat FTP Server 1.0 instances until a patch is available. 2. Implement network-level controls such as firewall rules to limit FTP traffic to trusted IP addresses and internal networks only. 3. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection to monitor for suspicious FTP APPEND command usage. 4. Consider migrating to more secure and actively maintained FTP server software that supports secure protocols like FTPS or SFTP. 5. If continued use is necessary, apply strict input validation and rate limiting on FTP commands where possible. 6. Monitor logs for unusual FTP activity indicative of exploitation attempts. 7. Prepare incident response plans to quickly isolate and remediate affected systems if exploitation is detected. 8. Stay updated with vendor advisories for patches or official workarounds and apply them promptly once available.