CVE-2025-55059 is a Cross-site Scripting (XSS) vulnerability classified under CWE-79, affecting Rumpus FTP Server version 9.0.12. The flaw stems from improper neutralization of user-supplied input during the generation of web pages served by the FTP server's management interface or web UI. This vulnerability allows an attacker with authenticated high privileges to inject malicious scripts that execute in the context of the victim’s browser session. The CVSS 3.1 base score is 4.8 (medium), reflecting that the attack vector is network-based (AV:N), requires low attack complexity (AC:L), but needs high privileges (PR:H) and user interaction (UI:R). The scope is changed (S:C), indicating that the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality and integrity to a limited extent (C:L, I:L), with no impact on availability (A:N). No public exploits or patches are currently available, increasing the urgency for monitoring and mitigation. The vulnerability could be exploited to steal session cookies, perform unauthorized actions on behalf of the user, or conduct phishing attacks within the trusted session. Since the vulnerability requires authentication and user interaction, it is less likely to be exploited remotely without insider access or social engineering. However, in environments where multiple users access the FTP server management interface, the risk is significant.

For European organizations, this vulnerability could lead to unauthorized disclosure of sensitive information such as session tokens or credentials, enabling attackers to impersonate legitimate users. This can compromise the integrity of FTP server management operations, potentially allowing attackers to manipulate configurations or access transferred files indirectly. Although availability is not impacted, the confidentiality and integrity breaches could disrupt business processes, especially in sectors relying on secure file transfers like finance, healthcare, and government. The requirement for high privileges and user interaction limits the attack surface but does not eliminate risk in environments with multiple administrators or users. Organizations with exposed or poorly segmented management interfaces are particularly vulnerable. The absence of known exploits reduces immediate risk but also means organizations should proactively apply mitigations to avoid future exploitation. Data privacy regulations such as GDPR increase the consequences of data breaches resulting from such vulnerabilities, potentially leading to regulatory penalties and reputational damage.

1. Restrict access to the Rumpus FTP Server management interface to trusted networks and IP addresses using firewall rules or VPNs. 2. Enforce strong authentication mechanisms and limit the number of users with high privileges to reduce the risk of insider threats. 3. Monitor logs and network traffic for unusual activity indicative of attempted XSS exploitation or unauthorized access. 4. Educate administrators and users about the risks of social engineering and phishing attacks that could facilitate exploitation. 5. Implement Content Security Policy (CSP) headers if configurable on the server to reduce the impact of injected scripts. 6. Regularly check for and apply vendor patches or updates as soon as they become available. 7. Consider deploying Web Application Firewalls (WAFs) capable of detecting and blocking XSS payloads targeting the FTP server’s web interface. 8. Conduct periodic security assessments and penetration testing focusing on the FTP server’s web components to identify and remediate similar vulnerabilities.