Methods, systems, and computer readable media for mitigating spoofing attacks on security edge protection proxy (sepp) inter-public land mobile network (inter-plmn) forwarding interface

A system for mitigating spoofing attacks on a security edge protection proxy (SEPP) inter-public land mobile network (inter-PLMN) forwarding interface, the system comprising:

• an SEPP including at least one processor and a memory;
• an SEPP inter-PLMN forwarding interface identity cross-validation database residing in the memory;
• and
• an inter-PLMN forwarding interface identity spoofing mitigation module implemented by the at least one processor and configured to:
• obtain, from at least one message received over an inter-PLMN control interface, at least one of a first SEPP identifier and a first PLMN identifier;
• store the at least one of the first SEPP identifier and the first PLMN identifier in an SEPP inter-PLMN forwarding interface identity cross-validation database;
• obtain, from at least one message received over the inter-PLMN forwarding interface, at least one of a second SEPP identifier and a second PLMN identifier;
• perform a lookup in the SEPP inter-PLMN forwarding interface identity cross-validation database using a lookup key comprising the at least one of the second SEPP identifier and the second PLMN identifier;
• and
• determine that a record corresponding to the lookup key is not present in the SEPP inter-PLMN forwarding interface identity cross-validation database, and, in response, prevent the at least one message received over the inter-PLMN forwarding interface from entering a PLMN protected by the SEPP.

A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer to perform steps comprising:

• obtaining, by a responding security edge protection proxy (SEPP) and from at least one message received over an inter-public land mobile network (inter-PLMN) control interface, at least one of a first SEPP identifier and a first PLMN identifier;
• storing the at least one of the first SEPP identifier and the first PLMN identifier in an SEPP inter-PLMN forwarding interface identity cross-validation database;
• obtaining, by the responding SEPP and from at least one message received over an inter-PLMN forwarding interface, at least one of a second SEPP identifier and a second PLMN identifier;
• performing a lookup in the SEPP inter-PLMN forwarding interface identity cross-validation database using a lookup key comprising the at least one of the second SEPP identifier and the second PLMN identifier;
• and
• determining that a record corresponding to the lookup key is not present in the SEPP inter-PLMN forwarding interface identity cross-validation database, and, in response, preventing the at least one message received over the inter-PLMN forwarding interface from entering a PLMN protected by the responding SEPP.