LTE Cloud Security

LTE.  Even the name is complex: Long-Term Evolution of Evolved Universal Terrestrial Radio Access Network

All LTE phones (UE, User Equipment) are running servers.  Multiple servers.  (And almost all are unsecured at the moment.)

Because of the proliferation of protocols (GSM, GPRS, CDMA, additional 3 and 4G, and now LTE), the overall complexity of the mobile/cell cloud is growing.

LTE itself is fairly complex.  The Protocol Reference Model contains at least the GERAN User Plane, UTRAN User Plane, and E-UTRAN User Plane (all with multiple components) as well as the control plane.  A simplified model of a connection request involves at least nine messages involving six entities, with two more sitting on the sides.  The transport layer, SCTP, has a four-way, rather than two-way, handshake.  (Hence the need for all those servers.)  Basically, though, LTE is IP, but a fairly complex set of additional protocols, as opposed to the old PSTN.  The old public telephone network was a walled garden which few understood.  Just about all the active blackhats today understand IP, and it’s open.  It’s protected by Diameter, but even the Diameter implementation was loopholes.  It has a tunnelling protocol, GTP (GPRS Tunnelling Protocol), but, like very many tunnelling protocols, GTP does not provide confidentiality or integrity protection.

Everybody wants to the extra speed, functions, interconnection abilities, and apps.  But all the functionality means a much larger attack surface.  The total infrastructure involved in LTE is more complex.  Maybe nobody can know it all.  But they can know enough to start messing with it.  From a simple DoS to DDoS, false billing, disclosure of data, malware, botnets of the UEs, spam, SMS trojans, even run down batteries, you name it.

As with VoIP before it, we are rolling our known data vulnerabilities, and known voice/telco/PBX vulnerabilities, into one big insecurity.

Share