Attacks on Telecom Operators and Mobile Subscribers via … 2015 Singapore/SyScan 2015... · Attacks on Telecom Operators and Mobile Subscribers via SS7 Dmitry ... • Huawei –45

Attacks on Telecom Operators and Mobile Subscribers via SS7

Dmitry KurbatovSecurity specialist

Positive Research

Yesterday: Closed Ecosystems

Today: Unified Technologies

Today: Common Interfaces

Today: IP Connectivity

Tomorrow: virtualization

SIGTRAN

Time Machine

Through SIGTRAN back to 1970’s

2014 was a good year for SS7 security

Hackito Ergo Sum 2014

• Locating mobile phones

Positive Hack Days IV

• How to Intercept a Conversation Held on the Other Side of the Planet

Washington Post

• Secretly track cellphones

31C3

• SS7: Locate. Track. Manipulate

• Mobile self-defense

Topics

USSD Money Transfer

Short Message Interception

DoS on Mobile Switching Center

Fraud in SS7 networkHot for mobile network operators

Hot for everyone

SS7

SS7 Network

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

SS7

HLRMSCVLR

Gateway MSC

Billing

SMS-C

Radio Part

A

B

Cell Phone

Base Transceiver Station

Base Station Controller

SS7

MSC/VLR

HLR

A

B

Gateway MSC

Billing

SMS-C

MSCVLR

Mobile Switching Center

Visitor Location Register

SS7

Gateway MSC

HLR

A

B

MSCVLR

Billing

SMS-CGateway

MSC

Gateway Mobile Switching Center

SS7

SMS-C

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

Short Message Service Center

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

Homeу Location Register

HLR

SS7

Billing

A

B

MSCVLR

Gateway MSC SMS-C

HLR

Billing

SS7

IDs

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

GT – Global Title 0 123 4567890

SS7

IDs

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C


MSISDN – A or B mobile numbers 0 123 4567890

SS7

IDs

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C



MSRN – Mobile Subscriber Roaming Number 0 123 4567890

SS7

IDs

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C



MSRN – Mobile Subscriber Roaming Number 0 123 4567890

IMSI – International Mobile Subscriber Identity 15 digits

SS7

How to get in?

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS Core

PS Core

IMS

Core Networks

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS

LTEWi-FiWiMAXPONDSLFemto

Access Networks

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS


GRX/IPX

Exchange Points

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS


GRX/IPXOAM

Remote support

Support

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS


GRX/IPXOAM

Remote support

IT IT network

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS


GRX/IPXOAM

Remote support

Internet

Internet IT network

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS


GRX/IPXOAM

Remote support

Internet

IT networkTraffic

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS


GRX/IPXOAM

Remote support

Internet

IT networkThreats

Attacker

Attacker

Attacker

Attacker

AttackerAttacker

SS7

HLR

A

B

MSCVLR

Gateway MSC

Billing

SMS-C

CS CoreUTRAN

PS Core

IMS


GRX/IPXOAM

Remote support

Internet

IT networkThreat

Attacker

Attacker

Attacker

Attacker

AttackerAttacker

SMS Interception

SS7

Collect info

HLR

Attacker

B

MSCVLR

Gateway MSC

We know

B-Number 0 123 4567802

A

SMS-C

SS7

Collect info

HLR

B

MSCVLR

Gateway MSC

1

1

SRI4SM

We know

B-Number 0 123 4567802Attackeras SMSC

A

SRI4SMsendRoutingInfoForSMI am SMSC.My GT 1 321 4567801.Where isSubscriber-B MSISDN 0 123 4567802?

SMS-C

SS7

Collect info

HLR

B

MSCVLR

Gateway MSC

1

1

2

SRI4SM

We know


sendRoutingInfoForSMI am HLR 0 123 4567800MSC/VLR 0 123 4567803Subscriber-B IMSI 15 digitsA

SS7

Collect info

HLR

B

MSCVLR

Gateway MSC

1

1

2

2

SRI4SM

We know

B-Number 0 123 4567802

HLR 0 123 4567800

MSC/VLR 0 123 4567803

Subscriber-B IMSI 15 digits

Attackeras SMSC

A


sendRoutingInfoForSMI am HLR 0 123 4567800MSC/VLR 0 123 4567803Subscriber-B IMSI 15 digits

SMS-C

SS7

Spoof MSC

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA

3

updateLocationI am MSC/VLR.My GT 1 321 4567801.I serve Subscriber-B IMSI 15 digits.

We know

HLR 0 123 4567800


SMS-C

SS7

Spoof MSC

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA

3

We know

HLR 0 123 4567800


HLR stores


MSC/VLR 1 321 4567801

4

Attacker serves Subscriber-B

SMS-C

SS7

SMS interception

HLR

B

MSCVLR

Gateway MSC

5

Attackeras MSC

A

SMS-C

5

“Hi, meet at 8pm at Baker Street”

SS7

SMS interception

HLR

B

MSCVLR

Gateway MSC

5 6

Attackeras MSC

A

sendRoutingInfoForSMI am SMSC.My GT 0 123 4567804.Where isSubscriber-B MSISDN 0 123 4567802?

SMS-C

5


SS7

SMS interception

HLR

B

MSCVLR

Gateway MSC

7

5 6

Attackeras MSC

A



SMS-C

5


HLR sends Attacker address instead of real MSC!

SS7

SMS interception

HLR

B

MSCVLR

Gateway MSC

7

5 6

8

Attackeras MSC

A



SMS-C

5


SMS-C routes this SMS to the received address.

SS7

SMS interception

HLR

B

MSCVLR

Gateway MSC

7

5 6

8

Attackeras MSC

A



SMS-C

5


SMS-C routes this SMS to the received address.

SMS interception

1. SMS chats

2. One time passwords

3. Notifications

4. Password recovery

Money Transfer Using USSD

SS7

Collect info

HLR

Attacker

B

MSCVLR

Gateway MSC

We know

B-Number 0 123 4567802

A

SS7

Collect info

HLR

B

MSCVLR

Gateway MSC

1

1

SRI4SM

We know


A


SS7

Collect info

HLR

B

MSCVLR

Gateway MSC

1

1

2

2

SRI4SM

We know

B-Number 0 123 4567802

HLR 0 123 4567800

MSC/VLR 0 123 4567803


Attackeras SMSC

A



SS7

Send USSD 1

HLR

Attackeras MSC/VLR

B

MSCVLR

Gateway MSCA

We know

HLR 0 123 4567800


*100#3

processUnstructuredSS-RequestI am MSC/VLR.Request how much money has subscriber with IMSI 15 digits?

SS7

Send USSD 1

HLR

Attackeras MSC/VLR

B

MSCVLR

Gateway MSCA


We know

HLR 0 123 4567800


Account info.3

4

processUnstructuredSS-RequestSubscriber’s account is $$$$$.

SS7

Send USSD 1

HLR

Attackeras MSC/VLR

B

MSCVLR

Gateway MSCA

We know

HLR 0 123 4567800


Account info.

4

processUnstructuredSS-RequestSubscriber’s account is $$$$$.


3

SS7

Send USSD 2

HLR

Attackeras MSC/VLR

B

MSCVLR

Gateway MSCA

We know

HLR 0 123 4567800


Account info.

*123*01238765400*100#

processUnstructuredSS-RequestI am MSC/VLR.Transfer money from IMSI 15 digits to my mobile account.

5

SS7

Send USSD 2

HLR

Attackeras MSC/VLR

B

MSCVLR

Gateway MSCA

We know

HLR 0 123 4567800


Account info.

6

processUnstructuredSS-RequestOK.


5

SS7

Send USSD 2

HLR

Attackeras MSC/VLR

B

MSCVLR

Gateway MSCA

We know

HLR 0 123 4567800


Real account info.

Subscriber B does not get SMS notification if Attacker combines this attack and the previous one.

6



5

SS7

Send USSD 2

HLR

Attackeras MSC/VLR

B

MSCVLR

Gateway MSCA

We know

HLR 0 123 4567800


Real account info.

Subscriber B does not get SMS notification if Attacker combines this attack and the previous one.

6



5

Mobile Switching Center DoS

SS7

Collect info

HLR

Attacker

B

Gateway MSC

We know

B-Number 0 123 4567802

MSCVLR

SS7

Collect info

HLR

Attackeras SMSC

B

MSCVLR

Gateway MSC

1

We know

B-Number 0 123 4567802


1

SS7

Collect info

HLR

B

MSCVLR

Gateway MSC

1

1

2

2

SRI4SM

We know

B-Number 0 123 4567802

HLR 0 123 4567800

MSC/VLR 0 123 4567803


Attackeras SMSC


SS7

Make it starve

HLR

Attackeras HLR

B

MSCVLR

Gateway MSC

We know

MSC/VLR 0 123 4567803


3PRNprovideRoamingNumberI am HLR.My GT 1 321 4567801.Provide MSRN forSubscriber-B IMSI 15 digits.

SS7

Make it starve

HLR

Attackeras HLR

B

MSCVLR

Gateway MSC

We know

MSC/VLR 0 123 4567803


MSRN 0 123 45600013PRN

4 provideRoamingNumberMSRN 0 123 4560001

SS7

Make it starve

HLR

Attackeras HLR

B

MSCVLR

Gateway MSC

We know

MSC/VLR 0 123 4567803


MSRN 0 123 45600013PRN

4

Default timeouts for MSRN:

• Ericsson – 30 sec

• Huawei – 45 secprovideRoamingNumberMSRN 0 123 4560001

SS7

Make it starve

HLR

Attackeras HLR

B

MSCVLR

Gateway MSC

We know

MSC/VLR 0 123 4567803


MSRN 0 123 4560001

…

MSRN 0 123 4569999

3PRN

4

provideRoamingNumberI am HLR.My GT 1 321 4567801.Provide MSRN forSubscriber-B IMSI 15 digits.


provideRoamingNumberI am HLR.My GT 1 321 4567801.Provide MSRN forSubscriber-B IMSI 15 digits.…

provideRoamingNumberMSRN 0 123 4560001provideRoamingNumber

MSRN 0 123 4560001provideRoamingNumberMSRN 0 123 4569999…

SS7

Make it starve

HLR

Attackeras HLR

B

MSCVLR

Gateway MSC

We know

MSC/VLR 0 123 4567803


MSRN 0 123 4560001

…

MSRN 0 123 4569999

3PRN

4


SS7

HLR

Attackeras HLR

B

MSCVLR

Gateway MSC

We know

MSC/VLR 0 123 4567803


MSRN 0 123 4560001

…

MSRN 0 123 4569999

3PRN

4

noRoamingNumberAvailable

Make it starve

SS7

HLR

Attackeras HLR

B

MSCVLR

Gateway MSC

We know

MSC/VLR 0 123 4567803


MSRN 0 123 4560001

…

MSRN 0 123 4569999

3PRN

4


Make it starve

SS7

DoS

HLR

Attackeras HLR

B

Gateway MSC

RealHLR

10k – 500k

MSCVLR

SS7

DoS

HLR

Attackeras HLR

Gateway MSC

PRNRealHLR

B

10k – 500k

MSCVLR

3

provideRoamingNumberI am HLR.My GT 1 321 4568701.Provide MSRN forSubscriber-ANY IMSI 15 digits.

SS7

DoS

HLR

Attackeras HLR

Gateway MSC

PRNRealHLR

B

10k – 500k

MSCVLR

3

4


SS7

DoS

HLR

Attackeras HLR

Gateway MSC

PRNRealHLR

B

10k – 500k

MSCVLR

3

4

No incoming calls

Sad calling party

Fraud in SS7

SS7

SS7 interconnection

HLRMSCVLR

Gateway MSC

Billing

SMS-C

HLRMSCVLR

Gateway MSC

Billing

SMS-C

HLRMSCVLR

Gateway MSC

Billing

SMS-C

Trusted environment

Leadership team

HLRMSCVLR

Gateway MSC

Billing

SMS-C

CEO

CSO CMO CCOCLO

Leadership team

HLRMSCVLR

Gateway MSC

Billing

SMS-C

CEO

CSO CMO CCOCLO

Really?!

Trust them?

Uncharged calls

SS7

Collect info

HLR

Attacker

B

MSCVLR

Gateway MSC

We know

B-Number 0 123 4567802

A

SS7

Collect info

HLR

Attackeras SMSC

B

MSCVLR

Gateway MSC

1

We know

B-Number 0 123 4567802


A

1

SS7

Collect info

HLR

B

MSCVLR

Gateway MSC

1

1

2

2

SRI4SM

We know

B-Number 0 123 4567802

HLR 0 123 4567800

MSC/VLR 0 123 4567803


Attackeras SMSC

A


SS7

Spoof MSC

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA

3


We know

HLR 0 123 4567800


SS7

Spoof MSC

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA

3


We know

HLR 0 123 4567800


SS7

Spoof MSC

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA

3

We know

HLR 0 123 4567800


HLR stores


MSC/VLR 1 321 4567801

4

Attacker serves Subscriber-B

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

GatewayMSC knows

nothing

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

5

6

sendRoutingInfoWhere isSubscriber-B MSISDN 0 123 4567802=Where is Subscriber-B located?

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

6

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

7 provideSubscriberInfoI am HLR.My GT 0 123 4567800.Provide location for theSubscriber-B.

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

6

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

7

8

provideSubscriberInfoSubscriber-B is in the Home network.

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

6

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

GatewayMSC knows that

Subscriber-B is at home.

This information will be sent to a billing platform.

7

8

8

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

5

9

sendRoutingInfoWhere isSubscriber-B MSISDN 0 123 4567802located =What is MSRN for Subscriber-B?

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

9

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801


10

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

9

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

provideRoamingNumberMSRN 39 0 654832169

10

11

SS7

Forward a call

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

9

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

GatewayMSC knows

Subscriber-B

MSRN 39 0 654832169

10

11

11

SS7

Forward a call to…Italy

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

9

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

GatewayMSC knows

Subscriber-B

MSRN 39 0 654832169

10

11

11

12

SS7

Forward a call to…

HLR

Attackeras MSC

B

MSCVLR

Gateway MSCA 5

9

provideRoamingNumber

MSRN 39 0 65483..

HLR stores

Subscriber-B

MSISDN 0 123 4567802

IMSI 15 digits

MSC/VLR 1 321 4567801

GatewayMSC knows

Subscriber-B

MSRN 39 0 654832169

10

11

Demo

Who pays?

ACall from to while at “home” = ₽ 1,60B

ACall from to = ₽ 30,00Italy

Who pays?

₽ 30,00 - ₽ 1,60 = ₽ 28,40 – Attacker profit



Who pays?

How much does a mobile operator lose?

₽ 30,00 - ₽ 1,60 = ₽ 28,40 – Attacker’s profit



International calls on 5,3% of original price

To Do:SS7 Firewall or IDS with evolution to IPS?

IDS Scheme

SS7 IDS & Event correlation

SS7 National

SS7 International

SS7 Other PLMNs

STP

STPSS7 taps

SS7 taps

SS7 taps

Duplicate traffic

Duplicate traffic

Duplicate traffic

Research Updates

• SS7 security threats

• Mobile Internet vulnerabilities (GPRS)

• SIM vulnerabilities

www.ptsecurity.com

http://blog.ptsecurity.com/



Dmitry [email protected]

Questions?

Attacks on Telecom Operators and Mobile Subscribers via … 2015 Singapore/SyScan 2015... · Attacks on Telecom Operators and Mobile Subscribers via SS7 Dmitry ... • Huawei –45

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