CVE-2025-65563 identifies a denial-of-service vulnerability in the open-source omec-project User Plane Function (UPF) component, specifically in the upf-epc/pfcpiface module up to version 2.1.3-dev. The vulnerability arises from improper input validation in the PFCP Association Setup Request handler. When the UPF receives a PFCP Association Setup Request message that lacks the mandatory NodeID Information Element, the handler dereferences a nil pointer instead of validating the message structure. This causes a runtime panic and terminates the UPF process, effectively crashing the user plane function. The PFCP protocol is used between the Control Plane and User Plane in 5G core networks, with the N4 interface being critical for session management and forwarding rules. An attacker capable of sending crafted PFCP messages to the UPF's N4/PFCP endpoint can exploit this flaw remotely without authentication or user interaction. The impact is a denial-of-service condition that disrupts user-plane traffic forwarding, potentially causing service outages or degraded network performance. The vulnerability is tracked as CWE-476 (NULL Pointer Dereference). Although no public exploits are reported yet, the CVSS v3.1 score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) indicates a high severity due to network attack vector, low complexity, no privileges or user interaction required, and high impact on availability. No patches are currently linked, so operators must monitor for updates or implement input validation workarounds. This vulnerability highlights the importance of robust protocol message validation in telecom software components.

For European organizations, particularly telecom operators and 5G network providers using the omec-project UPF, this vulnerability poses a significant risk to network availability. Exploitation can cause repeated crashes of the UPF, disrupting user-plane services that handle data traffic for mobile subscribers. This can lead to degraded service quality, dropped connections, and potential revenue loss. Critical infrastructure relying on 5G connectivity, including emergency services, IoT deployments, and enterprise communications, may experience interruptions. The lack of confidentiality or integrity impact limits data breach risks, but availability degradation in telecom core components can have cascading effects on dependent services. The vulnerability could also be leveraged in larger distributed denial-of-service (DDoS) campaigns targeting telecom infrastructure. European regulators and network operators must prioritize mitigation to maintain service continuity and comply with network resilience requirements.

1. Implement strict validation of PFCP Association Setup Request messages at the UPF N4 interface to ensure mandatory Information Elements like NodeID are present before processing. 2. Apply patches or updates from the omec-project as soon as they become available addressing this nil pointer dereference issue. 3. Deploy network-level filtering or rate limiting on the N4/PFCP interface to restrict or monitor incoming PFCP messages from unauthorized or suspicious sources. 4. Use anomaly detection systems to identify unusual PFCP traffic patterns indicative of exploitation attempts. 5. Conduct regular security audits and fuzz testing on protocol handlers to uncover similar input validation flaws. 6. Collaborate with vendors and open-source communities to accelerate patch development and share threat intelligence. 7. Prepare incident response plans for UPF service disruptions to minimize downtime and impact on end users. 8. Consider redundancy and failover mechanisms in UPF deployments to maintain user-plane availability during attacks.