CVE-2025-48040 is a vulnerability identified in the Erlang Open Telecom Platform (OTP), specifically affecting the ssh and ssh_sftp modules used for secure shell and file transfer operations. The vulnerability is categorized under CWE-400 (Uncontrolled Resource Consumption) and CWE-770 (Allocation of Resources Without Limits or Throttling). It allows an attacker to cause excessive resource allocation or flooding, potentially leading to denial of service conditions. The affected code resides in the ssh_sftpd.erl source file, which is part of the Erlang OTP ssh implementation. The vulnerability impacts OTP versions from 17.0 up to 28.0.3, including specific patch versions 27.3.4.3 and 26.2.5.15, and ssh package versions from 3.0.1 through 5.3.3 and related sub-versions. The CVSS v4.0 base score is 6.9, indicating a medium severity level. The vector string (AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N) shows that the attack can be performed remotely over the network without authentication or user interaction, with low attack complexity and limited impact on availability. The vulnerability does not affect confidentiality or integrity directly but can degrade service availability by exhausting system resources through uncontrolled allocation or flooding attacks. No known exploits are currently reported in the wild, and no patches have been linked yet, suggesting that mitigation may require vendor updates or configuration changes once available.

For European organizations, this vulnerability poses a risk primarily to systems running Erlang OTP with the affected ssh modules, which are often used in telecommunications, messaging platforms, and distributed systems. An attacker exploiting this vulnerability could cause denial of service by overwhelming the ssh service, leading to service disruptions or outages. This could affect critical infrastructure, cloud services, or enterprise applications relying on Erlang-based components. The impact is particularly significant for organizations with high availability requirements or those operating in sectors such as finance, telecommunications, and public services. Additionally, since the attack requires no authentication and can be launched remotely, the threat surface is broad, increasing the risk of widespread disruption if exploited at scale. The lack of known exploits currently reduces immediate risk but does not eliminate the potential for future attacks once exploit code becomes available.

European organizations should proactively audit their Erlang OTP deployments to identify affected versions of the ssh and ssh_sftp modules. Until official patches are released, mitigation can include implementing network-level controls such as rate limiting, connection throttling, and firewall rules to restrict access to ssh services to trusted IP ranges. Monitoring ssh service logs for unusual connection patterns or resource usage spikes can help detect attempted exploitation. Deploying intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics for anomalous ssh traffic may provide early warning. Organizations should also plan for timely patch management once vendor updates become available. Where feasible, isolating Erlang OTP ssh services in segmented network zones can limit the blast radius of potential attacks. Finally, reviewing and hardening system resource limits (e.g., process, memory, and file descriptor limits) can reduce the impact of resource exhaustion attempts.