CVE-2023-41591 is a critical vulnerability identified in the Open Network Foundation's ONOS (Open Network Operating System) version 2.7.0. This vulnerability allows an attacker to create spoofed IP and MAC addresses within the network managed by ONOS, enabling the execution of man-in-the-middle (MitM) attacks. ONOS is a software-defined networking (SDN) operating system designed to control network infrastructure programmatically. The flaw arises from insufficient validation or authentication mechanisms in ONOS that permit unauthorized entities to inject fake network addresses. By exploiting this vulnerability, an attacker can impersonate legitimate hosts on the network, intercept, modify, or redirect network traffic between genuine devices, thereby compromising confidentiality, integrity, and availability of communications. The CVSS v3.1 base score of 9.8 reflects the high severity, with network attack vector, no required privileges or user interaction, and full impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the potential for exploitation is significant given the critical role ONOS plays in managing network flows and policies in SDN environments. The CWE-290 classification indicates an authentication bypass or weakness, which aligns with the attacker's ability to spoof addresses without proper verification. The lack of patch information suggests that remediation may not yet be available or publicly disclosed, increasing the urgency for affected organizations to implement mitigations.

For European organizations, particularly those relying on SDN technologies like ONOS for their network infrastructure, this vulnerability poses a substantial risk. The ability to perform MitM attacks can lead to unauthorized data interception, manipulation of sensitive information, and disruption of critical network services. This can affect sectors such as telecommunications, financial services, government networks, and large enterprises that utilize SDN for network agility and control. The compromise of network traffic confidentiality and integrity could result in data breaches, regulatory non-compliance (e.g., GDPR violations), financial losses, and reputational damage. Additionally, the availability impact could disrupt business operations and critical communications. Given the increasing adoption of SDN in Europe for modernizing network infrastructure, the threat surface is expanding. The absence of known exploits currently may provide a window for proactive defense, but the high severity score necessitates immediate attention to prevent potential exploitation.

1. Network Segmentation: Isolate SDN controllers and critical network components from general user access and untrusted networks to limit attack surface. 2. Access Controls: Implement strict authentication and authorization mechanisms for ONOS management interfaces and APIs to prevent unauthorized access. 3. Monitoring and Anomaly Detection: Deploy network monitoring tools capable of detecting unusual IP/MAC address changes or suspicious traffic patterns indicative of spoofing or MitM attempts. 4. Use of Secure Channels: Ensure that communications between ONOS controllers and network devices use encrypted and authenticated channels (e.g., TLS) to prevent interception and tampering. 5. Vendor Coordination: Engage with ONOS maintainers or vendors to obtain patches or updates addressing this vulnerability as soon as they become available. 6. Incident Response Preparedness: Develop and test incident response plans specifically for network compromise scenarios involving SDN infrastructure. 7. Network Device Hardening: Configure network devices to validate MAC and IP addresses where possible, using features like Dynamic ARP Inspection (DAI) and IP Source Guard to prevent spoofing. 8. Regular Audits: Conduct periodic security audits and vulnerability assessments of SDN deployments to identify and remediate weaknesses proactively.