CVE-2025-44653 is a high-severity vulnerability affecting the H3C GR2200 MiniGR1A0V100R016 device, specifically related to its FTP server configuration. The vulnerability arises because the USERLIMIT_GLOBAL option in the /etc/bftpd.conf file is set to 0, which effectively disables any limit on the number of concurrent users connecting to the FTP service. This misconfiguration can be exploited by an attacker to initiate a Denial of Service (DoS) attack by overwhelming the FTP server with an unlimited number of simultaneous connections. Since the FTP daemon (bftpd) does not enforce a cap on user sessions, the server’s resources—such as CPU, memory, and network bandwidth—can be exhausted, leading to service degradation or complete unavailability. The CVSS v3.1 base score of 7.5 reflects a high severity, with the vector indicating that the attack can be performed remotely over the network (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and impacts availability only (A:H) without affecting confidentiality or integrity. The vulnerability is categorized under CWE-400, which relates to uncontrolled resource consumption. No known exploits are currently reported in the wild, and no patches have been linked yet. The affected product is a network device from H3C, a vendor known for enterprise-grade networking hardware, suggesting that this vulnerability could impact critical infrastructure components in enterprise environments.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on H3C GR2200 devices within their network infrastructure. The ability to cause a DoS condition remotely without authentication means attackers can disrupt FTP services, potentially halting file transfers, automated backups, or other business-critical operations that depend on FTP. This disruption can affect availability of services, leading to operational downtime, loss of productivity, and potential financial losses. Organizations in sectors such as telecommunications, manufacturing, and government agencies that use H3C networking equipment could face increased risk. Additionally, since the vulnerability does not compromise confidentiality or integrity, the primary concern is service availability, which can indirectly affect compliance with regulations like GDPR if service interruptions impact data processing or availability commitments. The lack of known exploits in the wild provides a window for mitigation, but the ease of exploitation (no privileges or user interaction required) means attackers could quickly weaponize this vulnerability once it becomes publicly known or if exploit code is developed.

To mitigate this vulnerability, European organizations should first audit their network infrastructure to identify any H3C GR2200 MiniGR1A0V100R016 devices in use. Immediate steps include reviewing the /etc/bftpd.conf configuration file on affected devices to verify the USERLIMIT_GLOBAL setting. Administrators should set a reasonable upper limit for concurrent FTP users to prevent resource exhaustion, for example, a value aligned with expected peak usage plus a safety margin. If direct configuration changes are not feasible, network-level controls such as rate limiting or connection throttling on FTP ports (usually TCP 21 and related data ports) can help mitigate the risk of DoS attacks. Monitoring tools should be configured to alert on unusual spikes in FTP connections or resource usage on these devices. Since no official patches are currently available, organizations should engage with H3C support for guidance and track vendor advisories for forthcoming updates. Additionally, consider segmenting FTP services behind firewalls or VPNs to restrict access to trusted users and reduce exposure to external attackers. Implementing intrusion detection/prevention systems (IDS/IPS) with signatures for anomalous FTP connection patterns can provide further defense.