OpenAirInterface version 2.2.0 accepts Security Mode Complete messages that declare no integrity protection when a network element receives a device capability of IA0. By allowing this insecure context the system can be coerced into accepting messages without integrity, which in turn permits an attacker to capture and later replay legitimate traffic, undermining data integrity.

The weakness specifically affects the OpenAirInterface implementation, version 2.2.0. Systems running this version are at risk if they allow devices that advertise only IA0 capability during registration. No proprietary vendor is listed, as the project is open source.

The vulnerability carries a high severity score of 7.5 and is considered unlikely to be widely exploited at present. It is not listed in the known exploited vulnerabilities catalog. An attacker would need network access to the 5G core and control or spoof a device that can send a registration request with IA0. Once the system accepts the request it will proceed without integrity checks, allowing replay of previously captured frames over the air interface.