Some Huawei 4G LTE devices, P30 versions before ELE-AL00 9.1.0.162(C01E160R1P12/C01E160R2P1) and P30 Pro versions before VOG-AL00 9.1.0.162(C01E160R1P12/C01E160R2P1), are exposed to a message replay vulnerability. For the sake of better compatibility, these devices implement a less strict check on the NAS message sequence number (SN), specifically NAS COUNT. As a result, an attacker can construct a rogue base station and replay the GUTI reallocation command message in certain conditions to tamper with GUTIs, or replay the Identity request message to obtain IMSIs. (Vulnerability ID: HWPSIRT-2019-04107)