CVE-2025-41068 is a reachable assertion vulnerability identified in Open5GS, an open-source 5G core network implementation widely used for research and some commercial deployments. The vulnerability affects versions up to 2.7.5 and resides in the Network Repository Function (NRF), which is responsible for maintaining a repository of available Network Functions (NFs) and enabling their discovery via the Service-Based Interface (SBI). An attacker with network connectivity to the NRF can exploit this vulnerability by sending a crafted request to create an NF with an invalid or unexpected type. Subsequently, when the attacker requests data related to this NF, the NRF performs an assertion check that fails, causing the NRF process to crash. This crash leads to a denial of service (DoS) condition, as the NRF becomes unresponsive and unable to provide discovery services to other network functions. The vulnerability is classified under CWE-617 (Reachable Assertion), indicating that the assertion failure can be triggered by external input. The CVSS 4.0 vector indicates no required privileges, no user interaction, and no confidentiality, integrity, or availability controls bypassed except for availability, which is highly impacted. The attack surface is the NRF's SBI, which is typically exposed within the operator's core network but could be reachable if network segmentation is insufficient. No known exploits are currently reported in the wild, but the ease of exploitation and critical role of the NRF make this a significant threat. The lack of available patches at the time of publication means operators must rely on network-level mitigations until vendor fixes are released.

The primary impact of CVE-2025-41068 is a denial of service against the NRF component of the 5G core network. The NRF is essential for service discovery and registration of network functions, so its unavailability can disrupt the operation of the entire 5G core, affecting subscriber connectivity, session management, and service delivery. For European organizations, particularly telecom operators and infrastructure providers deploying Open5GS or similar 5G core solutions, this vulnerability could lead to significant network outages, degraded service quality, and potential revenue loss. The disruption could also affect critical communications services, emergency response capabilities, and enterprise customers relying on 5G connectivity. Given the high reliance on 5G networks for digital transformation and IoT deployments in Europe, the impact extends beyond telecom operators to industries such as manufacturing, transportation, and healthcare. The vulnerability does not directly compromise confidentiality or integrity but severely impacts availability, which is critical for network reliability. The ease of exploitation without authentication increases the risk of opportunistic or targeted attacks, potentially by malicious insiders or external threat actors who gain network access. The lack of known exploits in the wild suggests a window for proactive mitigation, but the threat remains significant due to the critical nature of the affected component.

1. Immediate network segmentation: Restrict access to the NRF's Service-Based Interface (SBI) to trusted network segments only, using firewalls, VLANs, or software-defined networking controls to limit exposure. 2. Implement strict input validation and anomaly detection on SBI traffic to detect and block malformed or suspicious NF creation requests. 3. Monitor NRF process health and logs closely to detect crashes or assertion failures early and enable rapid incident response. 4. Deploy redundancy and failover mechanisms for the NRF to maintain service availability in case of crashes. 5. Engage with the Open5GS community and NewPlane vendor for patches or updates addressing CVE-2025-41068 and apply them promptly once available. 6. Conduct regular security assessments and penetration testing focused on 5G core components to identify similar vulnerabilities. 7. Limit administrative and network access to the NRF to authorized personnel and systems only, enforcing strong authentication and access controls. 8. Prepare incident response plans specifically for 5G core network disruptions, including communication strategies with customers and regulators. 9. Consider deploying network function virtualization (NFV) security best practices to isolate and protect critical 5G core functions. 10. Stay informed on threat intelligence related to Open5GS and 5G core vulnerabilities to adapt defenses proactively.