Integration of the layer 2 protection extended application for Open RAN: A security by design approach

The Open Radio Access Network (Open RAN) paradigm is progressively evolving to deliver open, intelligent, and innovative solutions for next-generation networks, particularly in 5G-Advanced and 6G. Spearheading this effort, the O-RAN Alliance has established a comprehensive framework for Open RAN and continues to lead standardization efforts in this domain. However, an analysis of the O-RAN security standard specifications reveals a primary focus on layer 3 and above, with an emphasis on IPsec protocols, leaving layer 2 security inadequately addressed. This gap exposes the E2 interface – a critical component enabling the openness and intelligence of Open RAN – to potential Man-in-the-Middle attacks at the layer 2. To mitigate this vulnerability, we propose a novel E2 protection xApp designed to enhance the security of the E2 interface. The proposed xApp detects and prevents layer 2 attacks, such as Address Resolution Protocol spoofing, ensuring robust protection for Open RAN environments. Experimental evaluations demonstrate that the proposed solution significantly improves network resilience, outperforming existing methods in mitigating layer 2 security vulnerability.