1. vSTP SS7 Security Guide
  2. GSMA Categorization
  3. Supported Message Categories
  4. Category 2

Category 2

This category includes messages that should only be received from visiting subscribers home network. These should normally only be received from an inbound roamer’s home network.

To handle the category 2 vulnerabilities, you must have the opcodes listed in Table 3-2. These opcodes ensures the following:
  • Blocking all messages from home-PLMN (messages where target IMSI is using the MCC+MNC of the own network.
  • Blocking all messages from home-PLMN for inbound roamers, where OperatorID referenced by all parameters in MAP and OperatorID in CgPA do not match.
  • Blocking the messages for which the HLRid is not consistent with the CgPA.

Following is the list of vulnerable category 2 opcodes:

Table 3-2 Message Category 2

opCode Originating SSN Destination SSN Description
provideRoamingNumber HLR MSC This opcode is used in FLOBR/TOBR feature.

when received from an HLR, the MAP message is screened for any Category 2 vulnerabilities.

Blocks the received HLR-to VLR provideRoamingNumber packets.

insertSubscriberData HLR MSC SGSN

This opcode is used in FLOBR/TOBR feature.

Blocks the insertSubscriberData packets with application context values 16, 1, or 32.
mt-forwardSM MSC MSC

This opcode is used in FLOBR/TOBR feature.
getPassword HLR MSC

This opcode is used in FLOBR/ToBR and Stateful Security Support (VLR Validation) features.

It blocks the SS related MAP packets.
reset      
unstructuredSS-Request HLR MSC SGSN

This opcode is used in FLOBR/ToBR and Stateful Security Support (VLR Validation) features.

It blocks the SS related MAP packets.
unstructuredSS-Notify HLR MSC SGSN

This opcode is used in FLOBR/ToBR and Stateful Security Support (VLR Validation) features.

It blocks the SS related MAP packets.