CVE-2025-55059 is a vulnerability classified under CWE-79, indicating improper neutralization of input during web page generation, commonly known as Cross-site Scripting (XSS). This flaw exists in Rumpus FTP Server version 9.0.12, a product used for file transfer services. The vulnerability allows an attacker with high privileges and authenticated access to inject malicious scripts into web pages generated by the server. When a victim interacts with these crafted pages, the malicious script executes in the victim’s browser context, potentially leading to unauthorized actions such as session hijacking, credential theft, or manipulation of displayed data. The CVSS v3.1 score is 4.8 (medium severity), reflecting that the attack vector is network-based, with low attack complexity but requiring high privileges and user interaction. The scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. Confidentiality and integrity impacts are low, while availability is unaffected. No public exploits or patches are currently available, but the vulnerability is officially published and reserved since August 2025. The vulnerability mainly affects the web interface of the FTP server, which is often used for administrative or file management tasks.

For European organizations, the impact of CVE-2025-55059 could include unauthorized access to sensitive session tokens or credentials via XSS attacks, potentially leading to further compromise of FTP server management or data exfiltration. Although the vulnerability requires authenticated access with high privileges, insider threats or compromised accounts could be leveraged by attackers. The confidentiality and integrity of data managed through the FTP server could be at risk, especially in sectors relying on FTP for sensitive file transfers such as finance, healthcare, and government. The lack of availability impact reduces the risk of service disruption, but the potential for lateral movement or escalation within networks remains. Organizations with exposed or poorly segmented FTP management interfaces are at higher risk. Given the medium severity and exploitation constraints, the threat is moderate but warrants proactive mitigation to prevent exploitation in targeted attacks.

1. Monitor for and apply vendor patches or updates as soon as they become available for Rumpus FTP Server version 9.0.12. 2. Restrict access to the FTP server’s web management interface to trusted IP addresses or VPN-only access to reduce exposure. 3. Enforce strong authentication mechanisms and regularly audit user privileges to minimize the risk of compromised high-privilege accounts. 4. Implement Content Security Policy (CSP) headers on the web interface to limit the execution of unauthorized scripts. 5. Conduct input validation and sanitization on all user-supplied data within the FTP server’s web interface to prevent injection of malicious scripts. 6. Use web application firewalls (WAFs) to detect and block common XSS attack patterns targeting the FTP server. 7. Educate administrators and users about phishing and social engineering risks that could lead to credential compromise. 8. Regularly review logs and monitor for unusual activity related to the FTP server’s web interface.