Good afternoon everyone

I get a new query regarding a type of attack that our freeswitch servers receive constantly in case someone knows how to block them.

These are INVITE or REGISTER requests in which the FROM: field arrives with the ip and port equal to the public interface of the server, so the different protection options that I have tried have not blocked these requests:

- IpTables can not filter by the information From the INVITE message.

- Fail2Ban is equally limited than IpTables.

- ACLs have not resolved to filter these requests.

Does anyone know any way to block these requests?

I send here a trace with an INVITE message where you can see a request of this type.

Thanks and best regards.

U 2017/12/14 18:32:55.156886 185.107.94.121:11120 -> 182.30.1.194:5060

INVITE sip:390239297988@ 182.30.1.194:5060;transport=UDP SIP/2.0.

Via: SIP/2.0/UDP 122.221.117.131:5060;branch=z9hG4bK-524287-1---xi3qy2kz737ni404.

Max-Forwards: 70.

Contact: <sip:15714000000@122.221.117.131:5060;transport=UDP>.

To: <sip:390239297988@ 182.30.1.194;transport=UDP>.

From: <sip:15714000000@ 182.30.1.194;transport=UDP>;tag=hlzg2jcv.

Call-ID: KaQqH51mAcFv34qN8cGyv3...

CSeq: 1 INVITE.

Content-Type: application/sdp.

User-Agent: Z 3.14.38765 rv2.8.3.

Allow-Events: presence, kpml, talk.

Content-Length: 0.

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