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</o:shapelayout></xml><![endif]--></head><body lang=ES link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Good afternoon everyone<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I get a new query regarding a type of attack that our freeswitch servers receive constantly in case someone knows how to block them.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>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:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>- IpTables can not filter by the information From the INVITE message.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>- Fail2Ban is equally limited than IpTables.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>- ACLs have not resolved to filter these requests.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Does anyone know any way to block these requests?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I send here a trace with an INVITE message where you can see a request of this type.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal>Thanks and best regards.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>U 2017/12/14 18:32:55.156886 185.107.94.121:11120 -> 182.30.1.194:5060<o:p></o:p></p><p class=MsoNormal>INVITE sip:390239297988@ 182.30.1.194:5060;transport=UDP SIP/2.0.<o:p></o:p></p><p class=MsoNormal>Via: SIP/2.0/UDP 122.221.117.131:5060;branch=z9hG4bK-524287-1---xi3qy2kz737ni404.<o:p></o:p></p><p class=MsoNormal><span lang=EN-US>Max-Forwards: 70.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Contact: <sip:15714000000@122.221.117.131:5060;transport=UDP>.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>To: <sip:390239297988@ 182.30.1.194;transport=UDP>.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>From: <sip:15714000000@ 182.30.1.194;transport=UDP>;tag=hlzg2jcv.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Call-ID: KaQqH51mAcFv34qN8cGyv3...<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>CSeq: 1 INVITE.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Content-Type: application/sdp.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>User-Agent: Z 3.14.38765 rv2.8.3.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Allow-Events: presence, kpml, talk.<o:p></o:p></span></p><p class=MsoNormal>Content-Length: 0.<o:p></o:p></p><p class=MsoNormal>.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div><div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br /> <table style="border-top: 1px solid #D3D4DE;">
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