The flaw is a buffer overflow triggered when the OpenAirInterface AMF processes a UplinkNASTransport carrying an Authentication Response whose NAS PDU is oversized, for example 100 bytes. The oversized payload is decoded by the AMF and then forwarded to the AUSF component for verification. Because the AUSF cannot handle the oversized data, it crashes, disrupting the authentication flow and preventing users from completing registration. The immediate impact is a denial of service to users relying on the affected network nodes.

OpenAirInterface software version 2.2.0, specifically the AMF component that forwards Authentication Responses to the AUSF. No other vendors or versions are specified.

The CVSS score is not provided, and EPSS data is unavailable, so the potential severity is known but exploitation likelihood is uncertain. The vulnerability is not listed in CISA’s KEV catalog, suggesting it is not yet known to be exploited in the wild. However, the repository indicates a critical issue that causes a crash. Based on the description, it is inferred that the attacker must be able to send a crafted Authentication Response to the AMF over the network. The attack can cause a temporary or persistent denial of service to users, potentially impacting network availability.