CVE-2022-43223 is a high-severity vulnerability identified in open5gs version 2.4.11, specifically within the ngap-handler.c component. Open5gs is an open-source implementation of 5G core network functions, widely used for research, development, and deployment of 5G networks. The vulnerability is a memory leak (CWE-401) triggered by processing a crafted User Equipment (UE) attachment request. This memory leak can be exploited remotely without authentication or user interaction, leading to resource exhaustion on the affected system. Over time, the leak can cause the open5gs process or the underlying system to become unstable or crash, resulting in a Denial of Service (DoS) condition. The CVSS v3.1 base score of 7.5 reflects the network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), but a high impact on availability (A:H). There are no known public exploits in the wild at the time of publication, and no official patches have been linked, indicating that mitigation may require manual code review or updates from the open5gs project. The vulnerability affects the core network's ability to handle UE attachment procedures, a fundamental step in 5G connectivity, making it critical for network stability and service availability.

For European organizations, especially telecom operators, mobile network infrastructure providers, and enterprises deploying private 5G networks, this vulnerability poses a significant risk. Exploitation can lead to service disruptions by causing DoS conditions in 5G core network components, impacting end-user connectivity and critical services relying on 5G. This can affect sectors such as telecommunications, manufacturing, transportation, and public safety, where 5G is increasingly integrated. The denial of service could degrade network reliability and availability, potentially causing cascading effects on dependent applications and services. Given the remote exploitability without authentication, attackers could launch attacks from outside the network, increasing the threat surface. The absence of confidentiality and integrity impact limits data breach risks, but availability degradation in critical infrastructure is a major concern under European cybersecurity regulations and service continuity requirements.

European organizations should prioritize the following mitigation steps: 1) Immediate assessment of open5gs deployments to identify affected versions, particularly version 2.4.11. 2) Engage with the open5gs community or maintainers to obtain patches or updates addressing this memory leak. If no official patch is available, consider applying temporary mitigations such as limiting UE attachment request rates via network-level filtering or firewall rules to reduce exposure to crafted requests. 3) Implement robust monitoring and alerting on open5gs processes for unusual memory consumption or crashes to detect exploitation attempts early. 4) Deploy network segmentation and access controls to restrict exposure of the 5G core network components to untrusted networks. 5) Conduct penetration testing and vulnerability scanning focused on 5G core components to identify potential exploitation paths. 6) Maintain incident response readiness to quickly isolate and remediate affected systems in case of DoS events. 7) Document and communicate the risk to stakeholders, ensuring compliance with European cybersecurity directives such as NIS2, which emphasize availability and resilience of critical infrastructure.