CVE-2025-54351 is a high-severity vulnerability affecting iperf3 versions prior to 3.19.1, specifically in the ES (Espressif Systems) project implementation. The vulnerability is classified under CWE-420, which pertains to unprotected alternate channels. The technical root cause lies in a buffer overflow condition within the net.c source file when the --skip-rx-copy option is used. This option relates to the handling of MSG_TRUNC in the recv system call, which is used to receive truncated messages. Improper handling of this scenario leads to a buffer overflow, allowing an attacker to potentially overwrite adjacent memory. According to the CVSS 3.1 vector (8.9, AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L), the vulnerability can be exploited remotely over the network without authentication or user interaction, but requires high attack complexity. The impact includes complete compromise of confidentiality and integrity, with limited impact on availability. The scope is changed, meaning the vulnerability can affect components beyond the initially vulnerable iperf3 process. No known exploits are currently reported in the wild, and no patches are linked yet, indicating that mitigation and remediation are critical to prevent future exploitation. iperf3 is widely used for network performance measurement and testing, often in enterprise, research, and telecommunications environments, making this vulnerability relevant for organizations relying on iperf3 for network diagnostics or performance validation.

For European organizations, the impact of CVE-2025-54351 can be significant, especially for those in sectors that rely heavily on network performance testing tools such as telecommunications providers, internet service providers, research institutions, and large enterprises with complex network infrastructures. Exploitation could lead to unauthorized disclosure of sensitive network performance data, manipulation of test results, or partial system compromise due to memory corruption. This could undermine network reliability assessments, lead to incorrect network optimization decisions, or serve as a foothold for further lateral movement within critical infrastructure. Given the vulnerability allows remote exploitation without authentication, attackers could target exposed iperf3 services on public or private networks. The high confidentiality and integrity impact could also affect compliance with European data protection regulations such as GDPR if sensitive data is exposed or altered. Although availability impact is low, the potential for data breach and system compromise elevates the risk profile for affected organizations.

1. Immediate upgrade to iperf3 version 3.19.1 or later once available, as this version addresses the buffer overflow issue. 2. Until patches are applied, disable the use of the --skip-rx-copy option in iperf3 configurations to prevent triggering the vulnerable code path. 3. Restrict network access to iperf3 services using firewall rules or network segmentation to limit exposure to untrusted networks. 4. Monitor network traffic for unusual iperf3 activity or attempts to exploit the MSG_TRUNC handling. 5. Employ runtime protections such as Address Space Layout Randomization (ASLR) and stack canaries on systems running iperf3 to mitigate exploitation impact. 6. Conduct thorough security assessments of network diagnostic tools and ensure they are included in vulnerability management programs. 7. Educate network administrators about the risks of using advanced iperf3 options that may expose vulnerabilities.