CVE-2025-54350 is a vulnerability identified in the iperf3 network performance measurement tool, specifically in versions prior to 3.19.1. The issue resides in the iperf_auth.c component, where a Base64Decode assertion failure occurs when the application processes a malformed authentication attempt. This assertion failure causes the application to exit unexpectedly. The vulnerability is categorized under CWE-617 (Reachable Assertion), which indicates that an assertion statement can be triggered by external input, potentially leading to denial of service (DoS) due to application termination. The CVSS v3.1 score for this vulnerability is 3.7, indicating a low severity level. The vector details (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L) show that the attack can be performed remotely over the network without privileges or user interaction, but requires high attack complexity. The impact is limited to availability, with no confidentiality or integrity loss. There are no known exploits in the wild, and no patches are currently linked, suggesting that mitigation may require updating to iperf3 version 3.19.1 or later once available. The vulnerability does not allow code execution or data compromise but can disrupt network performance testing by causing the tool to crash when faced with malformed authentication data.

For European organizations, the impact of CVE-2025-54350 is primarily related to operational disruption rather than data breach or system compromise. iperf3 is widely used for network performance testing and diagnostics in enterprise, telecommunications, and research environments. An attacker capable of sending malformed authentication attempts could cause iperf3 instances to crash, potentially interrupting network performance assessments or automated monitoring systems that rely on iperf3. This could delay troubleshooting or degrade network management efficiency. However, since the vulnerability does not allow unauthorized data access or persistent system compromise, the risk to confidentiality and integrity is minimal. Organizations with critical network infrastructure testing routines, especially those using iperf3 in automated or remote scenarios, may experience temporary denial of service conditions. The requirement for high attack complexity and lack of user interaction reduces the likelihood of widespread exploitation, but targeted attacks against network testing infrastructure remain a concern.

To mitigate CVE-2025-54350, European organizations should: 1) Upgrade iperf3 to version 3.19.1 or later as soon as the patch is available, since this version addresses the assertion failure. 2) Implement input validation and filtering at network boundaries to block malformed authentication attempts targeting iperf3 services, reducing exposure to crafted malicious packets. 3) Restrict access to iperf3 services to trusted networks or authenticated users to minimize the attack surface. 4) Monitor iperf3 logs and network traffic for unusual authentication failures or crashes that may indicate exploitation attempts. 5) Where possible, run iperf3 instances with limited privileges and in isolated environments to contain potential disruptions. 6) Incorporate fallback or redundancy in network performance monitoring to maintain operational continuity if iperf3 instances are disrupted.