110-6deploy-security-long v0 2 · 2010. 2. 18. · SSL/TLS protects web access Vi i i ff tiVirus...

IPv6 Security

110 Long Module on Security

IPv6 Security 1

Copy …RightsIPv6 Deployment and Support

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Thi lid t i th hi f th 6DISSThis slide set is the ownership of the 6DISS project via its partnersThe Powerpoint version of this material may beThe Powerpoint version of this material may be reused and modified only with written authorizationauthorizationUsing part of this material must mention 6DISS courtesyyPDF files are available from www.6deploy.orgLooking for a contact ?g

Mail to : [email protected] [email protected]

IPv6 Security 2

ContributorsIPv6 Deployment and Support

János Mohácsi, NIIF/HUNGARNET - HungaryO OOctavio Medina, Octavio Medina, Laurent Toutain, ENSTBernard Tuy, Jérôme Durand, Emmanuel Goiffon,Bernard Tuy, Jérôme Durand, Emmanuel Goiffon, RenaterPeter Kirstein, Steve Hailes, Piers O’Hanlon, UCLWolfgang Fritsche IABGWolfgang Fritsche, IABGJim Bound, Hewlett PackardPatrick Grostete, ArchrockPatrick Grostete, ArchrockMohsen Souissi, AFNICAlain Durand, Sun Microsystems Bill M i ISIBill Manning, ISIAlain Baudot, France Telecom R&DAnd many others

IPv6 Security 3

And many others

Table of ContentsIPv6 Deployment and Support

Introduction to Security Problems - 5The Security Threats - 24Mobile Computing and Access Control - 30Cryptographically Generated Addresses - 39Personal Area Networks - 44Unauthorized Access and Firewalls - 51Other threats - 62Transition mechanisms problems - 69Securing the Infrastructure with IPSEC - 73gConclusions and References – 85A short version - 88

IPv6 Security 4

IPv6 Security

Introduction to Security Problems

IPv6 Security 5

IntroductionIPv6 Deployment and Support

Security – isn’t it all solved?Conventional threatsWireless systems nowA i i f th f tA vision of the futureProtection nowProtection in the future

IPv6 Security 6

So what’s the big problem?IPv6 Deployment and Support

g pWe have firewalls and Intrusion Detection Systems – so we’re safe from outside attack VPNs, RADIUS, SSH, etc. allow secure remote accessPKI can be used to determine identityS/MIME PGP t t ilS/MIME or PGP protects mailSSL/TLS protects web accessVi i i ff tiVirus scanning is effectiveSecurity patches can be applied centrally – SMSIPv6 has complete built-in securityand it’s always sunny outside, pink bunnies play h il i t t ll ki d t ld l di

IPv6 Security 7

happily in streets, all are kind to old ladies

IPv6 Deployment and SupportWhy is there a problem?Lots of money + intellectual property (=money)Hostile environment (motivations for attack vary)Lack of security consciousnessLots of potential points of attackp pPolicies are often seen as unacceptableNo regulatory frameworkNo regulatory frameworkLegal aspects unclear

IPv6 Security 8

IPv6 Deployment and SupportWhy is there a problem?If b li th t ti ( fi llIf you believe that encryption (or firewalls or Intrusion Detection Systems) are the

t ll it bl thanswer to all your security problems, then you probably asked the wrong question.S it i b t i tSecurity is about securing a systemSecurity is a process NOT a productOOver-concentration on technology is deeply naïveHo e er if o do major changes like IP 4 IP 6However if you do major changes, like IPv4-IPv6, ensure you have not introduced new holes

IPv6 Security 9

IPv6 Deployment and SupportNetwork ThreatsPassive tapActive tappDenial of serviceF ki / lFaking/replayTraffic analysisy

IPv6 Security 10

IPv6 Deployment and SupportOther ThreatsPhysical attackTrojan Horses, viruses, worms, logic bombsPasswordsLoopholespCollusionAccidental accessAccidental accessTempestSocial EngineeringSocial Engineering

IPv6 Security 11

Cost Effective SecurityIPv6 Deployment and Support

yAbsolute security?

GIVE UP ON THE IDEA OF CERTAINTY, IT’SGIVE UP ON THE IDEA OF CERTAINTY, IT S FICTIONAL

Security = delay = cost to an attacker.But security costs implementer too.

So compromise on level of securityEvaluate risksEvaluate cost of lossesD ’ d h hiDon’t spend more than this

Hard --d ’t k ti ti f tt kdon’t know motivation of attackerdon’t know value of information or goodwill

IPv6 Security 12

Wireless systemsIPv6 Deployment and Support

y

Oh and then it all gets decidedly worse. AndOh and then it all gets decidedly worse. And the culprits?...

Toys!aka ‘empowering the workforce’

IPv6 Security 13

New problemsIPv6 Deployment and Support

p

I f t t d ’t t t d tInfrastructure doesn’t protect dataApplications can’t be trusted to secure dataN f f i ?New forms of virus?Security in mobile devices not standardised (many OS)(many OS)Devices easy to lose (or steal) or breakR di i b d t diRadio is a broadcast mediumMost mobile devices come with security disableddisabledData loss is painful; the more so the more one relies on it

IPv6 Security 14

relies on it

So what’s to be done?IPv6 Deployment and Support

Play Luddite? - Too lateWireless nodes will always be resource scarce compared to equivalent wired nodesActually, there is (going to be) a LOT of h t it i thiheterogeneity in this space

Low mobility high b/w devices (802.11)High mobility low b/w devices (cell phones to RFID tags)High mobility low b/w devices (cell phones to RFID tags)IPv4/IPv6 heterogeneous protocol suites

The UIs will not be getting significantly better (auThe UIs will not be getting significantly better (au contraire)There’s battery lifetime to consider (new DoS y (attacks)Much of it is going to look very different from now...

IPv6 Security 15

What is new with IPv6?IPv6 Deployment and Support

Security was considered from the beginning in y g gIPv6

One can rely on certain features existingWhen new services were considered, their security was part of IPv6 thinkingSome of the areas where the thinking is obvious are:

Th t t M bil d M bil IPThreats to Mobile access and Mobile IPCryptographically generated addressesProtocol for Authentication and Network AccessProtocol for Authentication and Network AccessIPsecMaking intrusion harder

IPv6 Security 16

Making intrusion harder

Security IssuesIPv6 Deployment and Support

ySame as ever – robustness

Authentication, Confidentiality, IntegrityNon-repudiationA t l ( th i ti )Access control (authorisation)Accounting/billing

B tButFocus is on ‘certainty’ – and it’s not clear we can have thatthatResource poverty – processing power/bandwidthActuators can kill peopleActuators can kill peopleLawful interception

IPv6 Security 17

Security issuesIPv6 Deployment and Support

y

Encryption, signatures etc. affected by resourcesVPNs and PKI work OK in principle (to the same extent as wired systems)same extent as wired systems)So does application level securityMalicious code – no ubiquitous approach

IPv6 Security 18

Traditional Way of Securing systemsIPv6 Deployment and Support

If we want to secure a system, then we need to y ,follow a number of principles:

Prevention is never 100% effective – so:Need defence in depth – several different mechanismsMechanisms for detecting and responding to attacks, preferably in real time, are essential:Start by securing the weakest linkStart by securing the weakest linkCompartmentalise – don’t put all of your data in one basketone basketMediocre security now is better than great security never

IPv6 Security 19

Take your users with you

Mechanisms for detecting and IPv6 Deployment and Support

gresponding to attacks

Detect – get to know you’re being attacked.Localise – determine what’s being attacked.Identify – determine who the attacker is.Assess – why are they doing this?y y gRespond or Prevent – depends on all of above.Recover – Have a plan better than ‘go find a newRecover – Have a plan better than go find a new job’Keep Audit Trail – so that you can assess theKeep Audit Trail – so that you can assess the damage

IPv6 Security 20

What changes in thisIPv6 Deployment and Support

Ambient computing = invisible computingBut heterogeneity in infrastructure, network protocols, etc.

Issues of scale mean that human intervention is largely impracticable. One needs:g y p

Autonomic mechanisms, new models of trustTo abandon the simple certainties ofTo abandon the simple certainties of conventional securityMechanisms to make intrusion more difficultMechanisms to make intrusion more difficult to do and easier to detectNew techniques to deal with mobility

IPv6 Security 21

New techniques to deal with mobility

Threats due to MobilityIPv6 Deployment and Support

y

Mobility in the system means changingMobility in the system means changing physical connectivity and logical context. It needs:needs:

Different types of policies; ones that can capture contextcapture context. Those policies implemented in a context dependent waydependent wayA flexible architecture to allow for composition of appropriate componentsof appropriate componentsSome assurance about how this will perform

Th bi i iIPv6 Security 22

There are big privacy issues

ConclusionIPv6 Deployment and SupportSecurity at present just about works

But it is a bolt on it has been a painful process toBut it is a bolt on – it has been a painful process to get here

Vision of futureVision of futuresystems of huge scale,with huge heterogeneitywith huge heterogeneity,and a bigger impact on our lives than ever before

N d R&D tl tNeed R&D urgently tothink what security means in these environmentsb ild it i t th t f d 1build security into these systems from day 1

Need public debate about impacts on society

IPv6 Security 23

IPv6 Security

The Security Threats

IPv6 Security 24

Threats to be Countered in IPV6IPv6 Deployment and SupportScanning gateways and Hosts for

weaknessScanning for multicast addressesExposing weaknesses with NATsExposing weaknesses with NATsUnauthorised accessWeaknesses in FirewallsPerformance attacks with fragmented headersProtocol WeaknessesDistributed Denial of Service

IPv6 Security 25

Scanning Gateways and HostsIPv6 Deployment and Support

Scanning Gateways and Hosts

Subnet Size is much larger About 500,000 years to scan a /64 , ysubnet@1M addresses/sec

But…But…NMAP does support IPv6 network scanningIPv6 Scanning methods are changing- IPv6 Scanning methods are changing

- DNS based, parallelised scanning, common numbering

- Compromising a router at key transit points- Can discover addresses in use

26IPv6 Workshop, Tbilisi

Scanning in IPv6IPv6 Deployment and Support

Scanning in IPv6IPv6 Scanning methods are likely to change

Public servers will still need to be DNS reachable giving attacker some hosts to attack – this is not new!Administrators may adopt easy to remember addresses (::1,::2,::53, or simply IPv4 last octet) EUI-64 address has “fixed part”EUI-64 address has fixed partEthernet card vendors guessNew techniques to harvest addresses – e.g. from DNS zones, logs

Deny DNS zone transferBy compromising routers at key transit points in aBy compromising routers at key transit points in a network, an attacker can learn new addresses to scan

Other possible network hiding: DNS splittingIPv6 Security 27

Other possible network hiding: DNS splitting

Scanning Multicast AddressesIPv6 Deployment and Support

g

New Multicast Addresses IPv6 supportsNew Multicast Addresses - IPv6 supports new multicast addresses enabling attacker to identify key resources on aattacker to identify key resources on a network and attack them

E.g. Site-local all DHCP servers (FF05::5), and All Routers (FF05::2)Addresses must be filtered at the border in order to make them unreachable from theorder to make them unreachable from the outside

IPv6 specs forbids the generation of ICMPv6 packets in response to messages to global multicast addresses that contain requests


Security of IPv6 addressesIPv6 Deployment and Support

y

C t hi ll G t d AddCryptographically Generated Addresses (CGA) IPv6 addresses [RFC3972]

Host ID part of address is an encoded hashHost-ID part of address is an encoded hashBinds IPv6 address to public key

Used for securing Neighbor DiscoveryUsed for securing Neighbor Discovery [RFC3971]Is being extended for other uses [RFC4581]

Private addresses as defined [RFC 4941]prevents device/user tracking from gmakes accountability harder

Host-ID could be token to access network


IPv6 Security

Mobile Computing and Access Control

IPv6 Security 30

Mobile IP (MIP)- IntentionIPv6 Deployment and SupportMobility

Growing number of mobile Internet usersM bilit t i th I t t i d

Mobile IP (MIP) Intention

Mobility support in the Internet requiredAddressing

Reachability of user under one fixed IPReachability of user under one fixed IP addressAutomatic configuration

Transparency

network A

TransparencyTransparent mobility support for users

Internetnetwork A

network B

IPv6 Security 31

MIPv6 – Home RegistrationIPv6 Deployment and SupportVisited network B

MIPv6 Home Registration

Home network A

BillInternet Bill

Home Agent Network CMapping

Mike

MappingBill‘s network A addressBill‘s network B address

MikeBill sends mapping to Home Agent (registration)

Home Agent confirms receipt of mapping and start to i k t f Bill ( )

IPv6 Security 32

receive packets for Bill (proxy)

MIPv6 – “Dog-leg” RoutingIPv6 Deployment and SupportVisited network B

g g g

Internet

Home network A Bill

N t k C

Internet

Home Agent Network C

Mike initiates communication to Bill and sends packets to Bill’s address on home network A

MikeHome Agent intercepts packets and bi-directionally tunnels them to Bill’s address on visited network B

IPv6 Security 33

MIPv6 – Optimised RoutingIPv6 Deployment and Support

Visited network

Home

p g

BillInternet

Home network A

Home Agent Network Cet o C

M i

Mike

MappingBill‘s network A addressBill‘s network B address

Bill sends mapping to Mike

Mike sends following packets directly to Bill’s address i it d t k B

IPv6 Security 34

on visited network B

MIPv6 – Attack ScenarioIPv6 Deployment and Support

Visited network BHome network A

Home Agent BillInternet

Network CNetwork D

Mike

MappingBill‘s network A address

Attacker‘s network D addressAttacker

Bill sends mapping to Mike

Attacker re directs traffic sent from Mike to Bill towards himself

IPv6 Security 35

Attacker re-directs traffic sent from Mike to Bill towards himself

MIPv6 – Trust RelationshipIPv6 Deployment and Support

Visited network B

p

Home

Visited network B

Internetnetwork A

Network C

No trust relationship between MN and CN --> ???Trust relationship between MN and HA --> IPSec can be used

IPv6 Security 36

No trust relationship between MN and CN --> ???

MIPv6 - Return routabilityIPv6 Deployment and Support

Visited network B

y

homenetwork A

Internetnetwork A

Network C

Home Test Init (HoT cookie)

Care of Test Init (CoT cookie)

Home Test (HoT cookie, home keygen token, home nonce index)

Care of Test (CoT cookie care of keygen token care of nonce index)

Care-of Test Init (CoT cookie)

IPv6 Security 37

Care-of Test (CoT cookie, care-of keygen token, care-of nonce index)

Mobile IPv6 – remaining security IPv6 Deployment and Support

Attacker on the path between HA and CN plus

g yissues

Attacker on the path between HA and CN plus between MN and CN will be able to receive all Return Routability packetsReturn Routability packets- This attacker could still send Binding information on behalf of the MNon behalf of the MNCryptographically Generate Addresses can help h ( lid )here (see next slides)- This still requires Return Routability itself to prove reachability of MN’s addresses

IPv6 Security 38

IPv6 Security

Cryptographically Generated Addresses

IPv6 Security 39

yp g p y

Cryptographically Generated IPv6 Deployment and Support

D fi d i RFC 3972 d t d b RFC4581&4982

Addresses (CGA) OverviewDefined in RFC 3972, updated by RFC4581&4982 IPv6 addresses, which carry hashed information about public key in the identifier partabout public key in the identifier part

Providing a binding of IP address to public key without requiring a full key management g y ginfrastructure

Provide for Secure Neighbor Discovery (SEND) –RFC 3971RFC 3971

Resolve chicken-egg problem of IPsecCould help to further secure Mobile IPv6 BindingCould help to further secure Mobile IPv6 Binding informationContinued work in IETF CSI Working Group

IPv6 Security 40

CGA - parametersIPv6 Deployment and Support

CGA Parameter data structure (RFC 3972)

p

CGA Parameter data structure (RFC 3972)Modifier

Chosen arbitrarily (16 octets)Chosen arbitrarily (16 octets) Address prefix

Prefix valid on the respective link (8Prefix valid on the respective link (8 octets)

Collision count (1 octet)Collision count (1 octet)Public key (Variable length)O ti l t i fi ld (V i bl l th)Optional extension fields (Variable length)

IPv6 Security 41

CGA – generation of Pub/Priv Key PairIPv6 Deployment and Support

1 Choose an arbitrary value for the 16 octet modifier

CGA generation of Pub/Priv Key Pair

1. Choose an arbitrary value for the 16 octet modifier2. Select an appropriate value for the security parameter (0:

« low resistance » to brute-force to 7: « high resistance to brute-force »brute-force »

3. Hash (SHA-1) concatenation of modifier, address prefix (set to zero), collision count (set to zero) and public key

4. If first 16 times security parameter bits are not zero, increase modifier by 1 and repeat hash computation (back to 4)

5 Hash (SHA-1) concatenation of final modifier real address5. Hash (SHA-1) concatenation of final modifier, real address prefix, collision count (set to zero) and public key

6. The identifier are the first 64 bits of the result with overriding the first 3 bits by the security parameter and setting u and gthe first 3 bits by the security parameter and setting u and g bit

7. If duplicate address detection fails, increase collision counter and go back to 6

IPv6 Security 42

and go back to 6

CGA structureIPv6 Deployment and Support

CGA - structure

Cryptographically Generated Address

Subnet prefix (64 bit) CGA specific ID (64 bit)

0 1 2 6 7

security „u“ bit „g“ bityparameter

„ „g

IPv6 Security 43

IPv6 Security

Personal Area Networks

IPv6 Security 44

PANA - overviewIPv6 Deployment and SupportIntention

E bl k h i iEnable network access authenticationProvide a link layer agnostic solution

Protocol aspectsProtocol aspectsPANA is an own protocolRuns on top of UDP / IPRuns on top of UDP / IPCarries EAP authentication messages (EAP MD5, EAP PEAP, EAP LEAP, EAP- TLS, EAP TTLS, …), , , , )Additional information in Attribute Value Pairs (Cookie, Protection-Capability, Device-ID, EP-Device ID EAP MAC Session ID )Device-ID, EAP, MAC Session ID, …)Supports separation of ISP and NAP authentication

IPv6 Security 45

authentication

PANA - architectureIPv6 Deployment and Support

PaC EP PAA

PANA architecture

PANA Authentication

Authorisation

PAA Discovery

PANAClient Enforcement

PointPoint

PANA Authentication

IPv6 Security 46

Agent

PANA - PAA discovery phaseIPv6 Deployment and Support

Client triggered

y p

PaC PAAPANA PAA Discovery

PANA Start Request [opt. Cookie]

PANA Start Answer [opt. Cookie]

Data / L2 triggeredPaC EP PAA

PANA PAA Discovery [device ID]

Data or L2 trigger

PANA Start Request [opt. Cookie]

PANA St t A [ t C ki ]

IPv6 Security 47

PANA Start Answer [opt. Cookie]

PANA - authentication phaseIPv6 Deployment and Support

PaC PAAPANA A th Req est [EAP req est]

p

PANA Auth Request [EAP request]

PANA Auth Answer [EAP response]

...PANA Auth Request [EAP request]

PANA Auth Answer [EAP response]

PANA Bind Request [EAP success, opt. protection]

PANA Bind Answer [opt. protection]

IPv6 Security 48

PANA - termination phaseIPv6 Deployment and Support

PAA triggered

p

PaC PAA

PANA T i ti R t [MAC]PANA Termination Request [MAC]

PANA Termination Answer [MAC][ ]

Client triggered

PaC PAA

PANA T i ti R t [MAC]PANA Termination Request [MAC]

PANA Termination Answer [MAC]

IPv6 Security 49

[ ]

PANA – open issuesIPv6 Deployment and Support

Separation between EP and PAARequires communication between bothNot in scope of the PANA specificationCOPS, SNMP, Diameter could be candidates hhere

Mobility supportIf client roams between different PAAs a reIf client roams between different PAAs a re-use of existing PANA session would be niceniceCommunication between involved PAAs requiredNot in scope of the PANA specificationContext Transfer Protocol potential

did tIPv6 Security 50

candidate

IPv6 Security

Unauthorised Access and Firewalls

IPv6 Security 51

Unauthorised Access control in IPv6IPv6 Deployment and SupportPolicy implementation in IPv6 with Layer 3

d L 4 i till d i fi lland Layer 4 is still done in firewallsSome design considerations! – see next slides

Filter site-scoped multicast addresses at site boundariesFilt IP 4 d IP 6 dd th iFilter IPv4 mapped IPv6 addresses on the wireMultiple address per interfaces

sshanyx:y:z:w::va:b:c:d::epermit

Dst portSrc portDstSrcAction

anyanydeny

IPv6 Security 52

Unauthorised Access control in IPv6IPv6 Deployment and Support

non routable + bogon address filteringnon-routable + bogon address filtering slightly different

in IPv4 easier deny non-routable + bogonin IPv6 easier to permit legitimate (almost)

host/net2001:db8::/32deny

Dst portSrc portDstSrcAction

serviceanyhost/net2002::/16permit

serviceanyhost/net2001::/16permit

ih t/ t2003 /16it serviceanyhost/net2003::/16permit

anyanydeny

serviceanyhost/net3ffe::/16permit

IPv6 Security 53

FirewallsIPv6 Deployment and Support

IPv6 architecture and firewall - requirementsNo need to NAT – same level of security with IPv6 possible as with IPv4 (security and privacy)

Even better: e2e security with IPSecEven better: e2e security with IPSecWeaknesses of the packet filtering cannot be hidden by NAThidden by NATIPv6 does not require end-to-end connectivity, but provides end-to-end addressabilitySupport for IPv4/IPv6 transition and coexistenceNot breaking IPv4 security

M t fi ll IP 6 blMost firewalls are now IPv6-capableCisco ACL/PIX, Juniper NetScreen, CheckPointModern OSes now provide IPv6 capable firewalls

54

Modern OSes now provide IPv6 capable firewallsIPv6 Security

IPv6 firewall setup - method1IPv6 Deployment and Support

DMZ

p

Internet

RouterProtectedNetwork

Firewall

Internet ↔router↔firewall↔net architectureRequirements:

Firewall must support/recognise ND/NA filteringFi ll RS/RA if S AAC i dFirewall must support RS/RA if SLAAC is usedFirewall must support MLD messages if multicast is required

IPv6 Security 55

multicast is required


p DMZ

Internet

Router Protected Network

Internet

Firewall

Internet ↔ firewall ↔ router ↔ net architectureRequirements:

Firewall must support ND/NAFirewall should support filtering dynamic routing

lprotocolFirewall should have large variety of interface types

IPv6 Security 56


p DMZ

Internet

Protected Network

Firewall+Router

Internet ↔ firewall/router(edge device) ↔ net architectureRequirements

Can be powerful - one point for routing and it li i SOHOsecurity policy – very common in SOHO

(DSL/cable) routersMust support what usually router AND firewall do

IPv6 Security 57

Must support what usually router AND firewall do

Firewall setupIPv6 Deployment and Support

p

No blind ICMPv6 filtering possible:No blind ICMPv6 filtering possible:

D b b tt i di tiN t t d ti ti

DebugEcho request/reply

Error report (e g E tension header errors)Parameter problem

Error reportTTL exceededDebug – better error indicationNo route to destination

⎤

Required for normal operation – except static ND entry

NS/NA

Error report (e.g. Extension header errors)Parameter problem

ific

d ⎤

ND entry

For Stateless Address AutoconfigrationRS/RA

iiv6 sp

eci

equi

red

Path MTU discoveryPacket too big

Requirements in for multicastMLD

⎡IP

v

⎡r

58

⎡

IPv6 Workshop, Tbilisi

Firewall setup 2IPv6 Deployment and Support

p

No blind IP options (→ extension Header) o b d opt o s (→ e te s o eade )filtering possible:

What to do with jumbograms or router alert Hop-by-hop header

Source routing – in IPv4 it is considered harmfulRouting header

option? – probably log and discard – what about multicast join messages?

Source routing – in IPv4 it is considered harmful, but required for IPv6 mobility – log and discard if you don’t support MIPv6, otherwise enable only Type 2 routing header for Home Agent of MIPv6

Routing header

Process according to the security policyAH headerProcess according to the security policyESP header

Type 2 routing header for Home Agent of MIPv6

All but last fragments should be bigger than 1280 octets

Fragment header

Process according to the security policyAH header

IPv6 Security 59

Interoperability of filtered applicationsIPv6 Deployment and Support

p y pp

FTPFTP:Very complex: PORT, LPRT, EPRT, PSV, EPSV, LPSV (RFC 1639, RFC 2428)virtually no support in IPv6 firewalls

HTTP seems to be the next generation file transfer protocol with WEBDAV andfile transfer protocol with WEBDAV and DELTAOther non tri iall pro able protocolOther non trivially proxy-able protocol:

no support (e.g.: H.323)

IPv6 Security 60

Overview of IPv6 firewallsIPv6 Deployment and Support

(a little out of date - things are getting better now)

1

CL X n XP

IPFi

lter 4

.

PF 3

.6

IP6f

w

Ipta

bles

Cis

co A

C

Portability Excellent Good Average Weak Weak Weak Weak Weak Weak

Cis

co P

IX7.

0

Juni

per

firew

all

Juni

per

Net

Scre

e

Win

dow

s SP

2

ICMP 6 Good Good Good Good Good Good Good Good Good

Excellent Excellent Good Excellent Excellent Excellent Good Excellent Weak

Excellent Excellent Good Excellent Excellent Excellent Excellent Excellent Good

ICMPv6 supportNeighbor DissoveryRS /RA

t Excellent Excellent Good Excellent Excellent Excellent Excellent Excellent Good

Good Good Good Excellent Good Good Good Good Weak

supportExtension header supportFragmantati CompleteWeak Weak Good Weak Average Weak Average Weak

Yes Yes No Yes Yes No

No No No ? No No No

tion support

Complete block

Stateful firewall

Csak USAGI

Reflexive firewall

ASP necessary

Next since 12.3FTP proxy No No No ? No No No

Oth

version (11)T

QOS support

QoS support, checking packet

Predefined rules in *BSD

EUI64 check,

Time based ACL

No TCP flag

support today, HW

IPSec VPN,

routing support

Graphical and central configuratio

n

IPv6 Security 61

Other vailidity based support n

IPv6 SecurityIPv6 Security

Other threats

IPv6 Security 62

Header Manipulation and Fragmentation Best Practices

IPv6 Deployment and Support

Fragmentation Best PracticesDeny IPv6 fragments destined to anDeny IPv6 fragments destined to an internetworking device - Used as a DOS vector to attack the infrastructurevector to attack the infrastructure Ensure adequate IPv6 fragmentation filtering capabilities. For example, drop all packets p p , p pwith the routing header if you don't have MIPv6Potentially drop all fragments with less than 1280 octets (except the last fragment)All f t h ld b d li d i 60All fragment should be delivered in 60 seconds otherwise drop

IPv6 Security 63

L3- L4 Spoofing in IPv6IPv6 Deployment and Support

p g

While L4 spoofing remains the same, IPv6 address are globally aggregated makingaddress are globally aggregated making spoof mitigation at aggregation points easy to deployto dep oyCan be done easier since IPv6 address is hierarchicalhierarchicalHowever host part of the address is not protectedprotected

You need IPv6 <– >MAC address (user) mapping for accountability!

IPv6 Security 64

y

Autoconfiguration/Neighbour DiscoveryIPv6 Deployment and Support

Neigbor Discovery ~ security ~ Address g y yResolution Protocol

No attack tools – ARP cache poisoningNo prevention tools – DHCP snooping

Better solution with SENDbased on CGA: token1=hash(modifier, prefix, public key, collision-count)y )Available in IOS-12.4(24)T, Linux/BSD (DoCoMo’s SEND Project)

DHCPv6 with authentication is possibleND with IPSec also possible

IPv6 Security 65

ND with IPSec also possible

Amplification (DDoS) AttacksIPv6 Deployment and Support

p ( )There are no broadcast addresses in IPv6

This would stop any type of amplificationThis would stop any type of amplification attacks that send ICMP packets to the broadcast addressGlobal multicast addresses for special groups of devices, e.g. link-local addresses, etc.

IPv6 specifications forbid the generationIPv6 specifications forbid the generation of ICMPv6 packets in response to messages to global multicast addressesmessages to global multicast addresses

Many popular operating systems follow the specificationStill uncertain on the danger of ICMP packets with global multicast source addresses


Mitigation of IPv6 amplificationIPv6 Deployment and Support

Mitigation of IPv6 amplification

Be sure that your host implementations follow the ICMPv6 spec [RFC 4443]p [ ]Implement Ingress Filtering

Defeats Denial of Service Attacks whichDefeats Denial of Service Attacks which employ IP Source Address Spoofing [RFC 2827]2827]

Implement ingress filtering of IPv6 packets with IPv6 multicast source addresswith IPv6 multicast source address


Other threatsIPv6 Deployment and SupportIPv6 Routing Attacks

Use traditional authentication mechanisms for BGP and IS-IS.Use traditional authentication mechanisms for BGP and IS IS.Use IPsec to secure protocols such as OSPFv3 and RIPng

Viruses and WormsSniffingg

Without IPsec, IPv6 is no more or less likely to fall victim to a sniffing attack than IPv4

ICMP attacks – slight differences with ICMPv4R d ti f Filt i ICMP 6 M i Fi ll (RFC4890)Recommendations for Filtering ICMPv6 Messages in Firewalls (RFC4890)TCP ICMP attacks – slight differences with ICMPv6

http://tools.ietf.org/html/draft-ietf-tcpm-icmp-attacksApplication Layer AttacksApplication Layer Attacks

Even with IPsec, the majority of vulnerabilities on the Internet today are at the application layer, (IPsec can’t help)

Man-in-the-Middle Attacks (MITM)( )Without IPsec, any attacks utilizing MITM will have the same likelihood in IPv6 as in IPv4

FloodingFlooding attacks are identical between IPv4 and IPv6

IPv6 Security 68

Flooding attacks are identical between IPv4 and IPv6

IPv6 Security

Transition Mechanisms Problems

IPv6 Security 69

Transition Mechanisms Problems

IPv6 transition mechanismsIPv6 Deployment and Support

~15 methods possible in combinationDual stack:Dual stack:

enable the same security for both protocolT lTunnels:

ip tunnel – punching the firewall (protocol 41)gre tunnel – probable more acceptable since used several times before IPv6

IPv6 Security 70

L3 – L4 Spoofing in IPv4 with 6to4IPv6 Deployment and Support

p g

For example via 6to4 tunneling spoofedFor example, via 6to4 tunneling spoofed traffic can be injected from IPv4 into IPv6.

IPv4 Src: Spoofed IPv4 Address pIPv4 Dst: 6to4 Relay Anycast (192.88.99.1)IPv6 Src: 2002:: Spoofed Source IPv6 Dst: Valid Destination

Attacke

IPv6 net public IPv4 IPv6 net

Attacker

IPv6 netnet

IPv6 net

6to4 relay6to4 gateway

IPv6 Security 71

6to4 relay6to4 gateway

Mixed IPv4/IPv6 environments IPv6 Deployment and Support

There are security issues with the transition h imechanisms

Tunnels are extensively used to interconnect networks over areas supporting the “wrong” et o s o e a eas suppo t g t e o gversion of protocolTunnel traffic many times has not been anticipated by the security policies It may pass throughby the security policies. It may pass through firewall systems due to their inability check two protocols in the same time

Do not operate completely automated tunnelsDo not operate completely automated tunnelsAvoid “translation” mechanisms between IPv4 and IPv6, use dual stack insteadOnly authorized systems should be allowed as tunnel end-pointsAutomatic tunnels can be secured by IPSec

IPv6 Security 72

Automatic tunnels can be secured by IPSec

IPv6 Security

IPSEC Infrastructure

IPv6 Security 73

IPSecIPv6 Deployment and Support

general IP Security mechanismsprovides

authenticationconfidentialityconfidentialitykey management - requires a PKI infrastructure (IKE) –new simplified and unified IKEv2 will be available soon.

applicable to use over LANs, across public & private WANs, & for the InternetIPSec is not a single protocol. Instead, IPSec provides a set of g p , psecurity algorithms plus a general framework that allows a pair of communicating entities to use whichever algorithms provide security appropriate for the communication.p y pp pIPSec is mandated in IPv6 – you can rely on for e2e security

But some like 3G may not use it after all!

IPv6 Security 74

IPsec protocol overviewIPv6 Deployment and Support

pIPsec services

AuthenticationAH (Authentication Header - RFC 4302)

ConfidentialityESP (Encapsulating Security Payload - RFC 4303)

Replay protection IntegrityReplay protection, IntegrityKey management

IKEv2 (Internet Key Exchange - RFC4306)IKEv2 (Internet Key Exchange RFC4306)IPsec modes: Transport Mode & Tunnel Mode

ImplementationspLinux-kernel (USAGI), Cisco IOS-12.4(4)T, BSD&OSX(Kame)


IPsec Architecture (RFC 2401)IPv6 Deployment and Support

( )

S it P li i Whi h t ffi i t t d?Security Policies: Which traffic is treated?

S it A i ti H i t ffi d?Security Associations: How is traffic processed?

Security Protocols: Which protocols (extension headers) are used?

Key Management: Internet Key Exchange (IKE)

Algorithms: Authentication and Encryption

IPv6 Security 76

IPsec ModesIPv6 Deployment and Support

Transport Mode Tunnel Mode

Above the IP levelBelow the Transport level

IP within IPBelow the transport levelBelow the Transport level

Only the IP datagram All the tunneled IP y gpayload is protected datagram is protected

IPv6 Security 77

IPsec Scenarios - Scenario 1: H2HIPv6 Deployment and Support

End-to-end serviceTransport/Tunnel mode between the 2 hosts

Transport or Tunnel

R1H1 H2R2

L lLocalIntranet The

InternetLocal

Intranet

IP header IPsec ext AH/ESP Payload

IPv6 Security 78

AH/ESP

IPsec Scenarios - Scenario 1: H2HIPv6 Deployment and Support

End-to-end serviceTransport/Tunnel mode between the 2 hosts

Transport or Tunnel

R1H1 H2R2

L lLocalIntranet The

InternetLocal

Intranet

IP header PayloadIPsec ext AH/ESP

Inner IP header

IPv6 Security 79

AH/ESP header

IPsec Scenarios - Scenario 2: G2GIPv6 Deployment and Support

VPN, Site-to-Site/ISP agreements, …, g ,Tunnel between the 2 gateways

G1H1 H2G2

Tunnel

G1H1 H2G2

LocalI t t The LocalIntranet The

InternetLocal

Intranet


Inner IP header

IPv6 Security 80

AH/ESP header

IPsec Scenarios - Scenario 3: H2G, G2HIPv6 Deployment and SupportDial-in users

Tunnel between the “external” host and theTunnel between the external host and the gateway

Tunnel

H1 H2G

TheInternet

LocalIntranet


Inner IP header

IPv6 Security 81

AH/ESP header

IPsec ProtocolsIPv6 Deployment and SupportAuthentication Header (AH)

RFC 4302Encapsulation Security P l d H d (ESP)RFC 4302

Protocol# (Next Header) = 51

Provides:

Payload Header (ESP)RFC 4303

Protocol# (Next Header) = 50Provides:Connectionless IntegrityData origin authenticationReplay protection

Provides:Connectionless IntegrityD t i i th ti tiReplay protection

Is insertedIn Transport mode: After

Data origin authenticationReplay protectionConfidentialityIn Transport mode: After

the IP header and before the upper layer protocol (UDP, TCP, …)

Is insertedIn Transport mode: After the IP header and before the upper layer protocol( )

In Tunnel mode: Before the original IP header (the entire IP header is protected)

the upper layer protocolIn Tunnel mode: before an encapsulated IP header

IPv6 Security 82

protected)

IPsec: Protocols, services & modes IPv6 Deployment and Support

combinationsTransport Mode Tunnel Mode SA

AH Authenticates IP pa load and

Authenticates entire inner IP datagrampayload and

selected portions of IP header

inner IP datagram (header + payload), + selected portions of the outer IP header

ESP Encrypts IP payload Encrypts inner IPESP Encrypts IP payload Encrypts inner IP datagram

ESP ith Encrypts IP payload Encrypts andESP with Authentication

Encrypts IP payload and authenticates IP payload but not IP h d

Encrypts and authenticates inner IP datagram

IPv6 Security 83

IP header

IPsec : Key ManagementIPv6 Deployment and Support

y g

M lManualKeys configured on each system

Automatic: IKE or IKEv2 (Internet Key Exchange, RFC 4306)( y g , )Combines previously separate documents: Internet Security Association and Key Management Protocol (ISAKMP, RFC 2408), IKE (RFC 2409), the Internet Domain of Interpretation2408), IKE (RFC 2409), the Internet Domain of Interpretation (DOI, RFC 2407), Network Address Translation (NAT) Traversal, Legacy authentication, and remote address acquisition. qVersion 2 of IKE does not interoperate with version 1, but it has enough of the header format in common that both versions can unambiguously run over the same UDP port.versions can unambiguously run over the same UDP port.

Algorithms: Authentication and Encryption

IPv6 Security 84

IPv6 Security infrastructureIPv6 Security infrastructure

Conclusions and the referencesIPv6 Security 85

Conclusions and the references

SummaryIPv6 Deployment and Support

SummaryIPv6 has potential to be a foundation of 6 pa more secure InternetElements of the IPv6 securityElements of the IPv6 security infrastructure are mature enough to be deployed in production environment.deployed in production environment.

Firewalls, IPSec, AAA, Mobile IP etc.Other elements are in prototype stateOther elements are in prototype state

CGA, PANA, VPNsBut even these are ready for experimentalBut even these are ready for experimental

deployment

IPv6 Security 86

A Few Specific ReferencesIPv6 Deployment and Support

p6NET D3.5.1: Secure IPv6 Operation: Lessons learned from 6NETJ Mohacsi “IPv6 firewalls” presentation on the 5th TFJ. Mohacsi, “IPv6 firewalls”, presentation on the 5th TF-NGN meeting, October 2001 available at http:///skye.ki.iif.hu/~mohacsi/athens_tf_ngn_ipv6_firewalls pdfs.pdfJ.Mohacsi, “Security of IPv6 from firewalls point of view”, presentation on TNC2004 conference, June 2004, available atavailable at http://www.terena.nl/conferences/tnc2004/programme/presentations/show.php?pres_id=115 6NET D6 2 2: Operational procedures for secured6NET D6.2.2: Operational procedures for secured management with transition mechanismsS. Convery, D Miller, IPv6 and IPv4 Threat Comparison and Best Practice Evaluation (v1 0)" presentation at theand Best-Practice Evaluation (v1.0) , presentation at the 17th NANOG, May 24, 2004János Mohácsi, Elwyn Davis: Draft-v6ops-icmpv6-filtering bcp 00 txt

IPv6 Security 87

filtering-bcp-00.txt

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