81 slides 40 Years of Internet Arms Races… Bill Cheswick [email protected] .

81 slides

40 Years of Internet Arms Races…

Bill Cheswick

[email protected]

http://www.lumeta.com

81 slides

Thinking about security…

3 of 8140 Years of Internet Arms Races

Talk outline

• Intro

• Some thoughts on thinking bad thoughts

• Various races

• Predictions– You got that with the 40 years, right?

• Wishes–My dad’s computer, and Windows OK–Windows SP2


Since some of you asked…

• Chief Scientist at Lumeta, a Bell Labs spin-off– Founded in 2000. 45 people in the

company

• We map large corporate and government networks, and find leaks in the network perimeter

• I am still figuring out what a chief scientist does

• Second edition of the firewalls book came out last year: Cheswick, Bellovin, Rubin


Before the whining and predicting, something useful

• Lost friends web page

• Cheap research web pages

• Please give me feedback if I get something wrong– I do get out much from my little Internet

startup (Lumeta)– You folks keep me honest.

81 slides

Security People are Paid to Think Bad

Thoughts

-Bob Morris

81 slides

Fred Cohen and me


What do you do with bad thoughts?

• The world is full of threats

• One can get a bit pessimistic

• CIA asked a number of us for some of our bad thoughts

• Watch your ethics! Are you battling the forces of darkness?


Questions about an evil idea

• Has it already been done? How would you detect it?

• If not, why hasn’t it happened yet?

• What are the strategic preparations needed?

• What are the tactical preparations needed just before the attack?

• Can we detect strategic preparations?

• Can we detect tactical preparations?


Minor example: Internet mapping


Minor example: Internet Mapping Project

• Hal Burch and me, since 1998

• AUCERT has corresponded (complained) to us a number of times

• Basic technology: 250,000 traceroutes/day

• Question: who else is doing this?


10:45:42 udp 5 uma1.co.umatilla.or.us11:28:12 udp 1 64.d9b7d1.client.atlantech.net10:57:05 udp 43101:24@0+ omval.tednet.nl10:57:05 udp 43101:1456@24+ omval.tednet.nl10:57:05 udp 43101:625@1480 omval.tednet.nl11:30:59 udp 7 ns1.yamato.ibm.com


Minor example: Internet Mapping Project

• Andrew Gross and rstatd


Some thoughts on computing safety

• Morris worm at Bell Labs (1988)

• “Best block is not be there”– Karate Kid I

• “You got to get out of the game”– Fred Grampp

• I’ve never detected a virus or worm on one of my important systems.


Don’t let opposition practice on you during an arms race

• Dictionary attacks on passwords

• Crashme tests on programs, protocols, and operating systems–Weakness using COTS!


The Internet security arms race

• Defenders can control the battlefield

• An uneasy truce may be good enough, if the business case can make usable predictions


The Internet is a fine place to practice attacks

• Automated

• Anonymous

• Many “volunteers”

• Don’t give them a dictionary, “oracle”, or “cribs” to try automated attacks on

• Monoculture of software in hosts and routers


The Internet is a fine place to practice defenses

• MILnet has been under attack since the mid-1980s

• That makes the threats much clearer

• It gives the defenders a chance to get good at their job

81 slides

Arms Races:Eavesdropping


Arms race:Eavesdropping

• Ethernet, ftp, and telnet were poor starts

• WEP, POP3, IMAP, AIM added to the confusion– POP3 passwords are the most common I

sniff over the air at conferences like this

• Crypto wars of the mid-1990s tied our hands

• This race should be over, victory to the defenders


Eavesdropping victories

• SSL ends direct credit card sniffing

• Ssh lets me access secure machines from anywhere

• IP/SEC is a bit of a pain to deploy, but that should get better– VPN products are very useful

• CPUs have plenty of spare power now.

• Check your work with dsniff


Eavesdropping problems

• Casual web access and DNS queries still mostly in the clear.

• Most ISPs still offer or insist on POP3 and IMAP, not SSL versions of these

• Widespread use of client certificates could limit access to these possibly dangerous network services


Eavesdropping arms races

• Attack patterns vs. snort

• Tcpdump/libpcap vs. killer packets

81 slides

Arms Race: Battle for control of the

computer and data


The battle for control of the computer

• Who owns the software in your computer? Who should be allowed to add and run programs?– Microsoft has assumed this since DOS

• Viruses and worms

• Pop-overs and pop-unders

• Spyware

• Automatic update systems

• Same battle over data in computers controlling your car– Thermostat? Front door lock? Toaster?


Goals for this extraware

• Zombie nets to assist with malfeasance, including forwarding of spam

• Collect marketing data

• Display advertisements

• Enforce licensing restrictions


Solution: operating system only executes known programs

• Virus problem goes away

• Unix/Linux systems mostly do this already

• OS updates and auxiliary program installs a problem

• This feature not available on Microsoft operating systems (see below)


Extraware problems

• Some business practices assume this ability is available

• Some web page writers assume that I am willing to use possibly dangerous features in my browser (or a particular browser)


Virus arms race

• Early on, detectors used viral signatures

• Virus encryption and recompilation (!) has thwarted this

• Virus detectors now simulate the code, looking for signature actions

• Virus writers now detect emulation and behave differently

• Virus emulators are slowing down, even with Moore’s Law.


Virus arms race

• I suspect that virus writers are going to win the detection battle, if they haven’t already– Emulation may become too slow– Even though we have the home-field advantage– Will we know if an undetectable virus is released?

• Best defense is to get out of the game.– Don’t run portable programs, or– Improve our sandbox technology

• People who really care about this worry about Ken Thompson’s attack– Read and understand “On Trusting Trust”


The emulation arms race

• Vmware versus the real thing– 4tphi

• Honeypots vs. bulkers– http://www.sendsafe.com/honeypot-hunter

.php

81 slides

Arms Race:Authentication and

identification


Password cracking

• Works 3% to 60% of the time using offline dictionary attacks–More, if the hashing is misdesigned

• This will never get better, so…

• We have to get out of the game


Passwords sniffed at this conference


Authentication/Identification Arms races

• Password/PIN selection vs. cracking

• Human-chosen passwords and PINs can be ok if guessing is limited, and obvious choices are suppressed

• Password cracking is getting better, thanks to Moore’s Law and perhaps even botnets


Colossus(ver 2.0)

TonySale


We don’t know how to leave the user in charge of security decisions, safely.


Authentication solutions:two factor authentication

• In my laptop: ssh key unlocked by long passphrase

• Better: USB “key” unlocked by PIN. Five bad PINS, and it is gone.–We already carry a bunch of keys, so why

not one more


Hardware tokens

• These need to be open source drivable, and cheap

• The business model has never been one for global adoption

• Challenge/response form factor is the safest, but not acceptable if humans are in the loop


Authentication arms race:predictions

• We’ve already won this, from a business model standpoint–Web SSL plus password is good enough

for banking

• USA needs two factor authentication for social security number. (Something better than MMN or birth date.)

• I don’t see this improving much, but a global USB dongle would do it

• Don’t wait for world-wide PKI.

81 slides

Arms race (sort of):destructible hardware


Arms race (sort of)hardware destruction

• IBM monochrome monitor

• Some more recent monitors– Current ones?

• Hard drives? Beat the heads up?

• EEPROM write limits– Viral attack on .cn and .kr PC

motherboards–Other equipment

• Anything that requires a hardware on-site service call


Arms race (sort of)hardware destruction

• Rendering the firmware useless– This can be fixed (mostly) with a secure

trusted computing base.


Software upgrade race: literally a race

• Patches are analyzed to determine the weakness

• Patch-to-exploit time is now down below 10 hours– NB: spammers have incentive to do this

work

• Now the good guys are trying to obfuscate code!

• Future difficult to say: dark side obscures everything.


Arms Races:firewalls

• IP blocking

• Ip aware (stateful)–More dangerous– Permits firewalking

• Ultimately, firewalls are a hack, and should go away

81 slides

Arms Races:deception


West coralSnake

Scarlet king snake

81 slides

(the west coral snake is venomous)


Arms Races: deception

• Jails– Cliff Stoll and SDInet

• Honeypots– Honeynet– honeyd

• The deception toolkit---Fred Cohen


Bulkers vs honeypots

• http://www.send-safe.com/honeypothunter.php


User education vs. user deception

• We will continue losing this one

• Even experts sometimes don’t understand the ramifications of choices they are offered


Historic Arms races

• SYN packet attacks

• TCP sequence number guessing

81 slides

My Dad’s computer

Skinny-dipping with Microsoft


Case study:My Dad’s computer

• Windows XP, plenty of horsepower, two screens

• Applications:– Email (Outlook)– “Bridge:” a fancy stock market monitoring

system– AIM

• Cable access, dynamic IP address, no NAT, no firewall, outdated virus software, no spyware checker


This computer was a software toxic waste dump

• It was burning a liter of oil every 500 km

• The popups seemed darned distracting to me

• But he thought it was fine–Got his work done– Didn’t want a system administrator to

break his user interface somehow

81 slides

A proposal:Windows OK


Windows OK

• Thin client implemented with Windows

• It would be fine for maybe half the Windows users– Students, consumers, many corporate

and government users

• It would be reasonable to skinny dip with this client–Without firewall or virus checking

software


Windows OK

• No network listeners– None of those services are needed, except

admin access for centrally-administered hosts

• Default security settings

• All security controls in one or two places

• Security settings can be locked


Windows OK (cont)

• There should be nothing you can click on, in email or a web page, that can hurt your computer– No portable programs are executed ever,

except…

• ActiveX from approved parties–MSFT and one or two others. List is

lockable


Windows OK

• Reduce privileges in servers and all programs

• Sandbox programs– Belt and suspenders


Office OK

• No macros in Word or PowerPoint. No executable code in PowerPoint files

• The only macros allowed in Excel perform arithmetic. They cannot create files, etc.


Vulnerabilities in OK

• Buffer overflows in processing of data (not from the network)

• Stop adding new features and focus on bug fixes

• Programmers can clean up bugs, if they don’t have a moving target– It converges, to some extent

81 slides

Microsoft client security

It has been getting worse: can they skinny-dip safely?


Windows MEActive Connections - Win ME

Proto Local Address Foreign Address State TCP 127.0.0.1:1032 0.0.0.0:0 LISTENING TCP 223.223.223.10:139 0.0.0.0:0 LISTENING UDP 0.0.0.0:1025 *:* UDP 0.0.0.0:1026 *:* UDP 0.0.0.0:31337 *:* UDP 0.0.0.0:162 *:* UDP 223.223.223.10:137 *:* UDP 223.223.223.10:138 *:*


Windows 2000

Proto Local Address Foreign Address State TCP 0.0.0.0:135 0.0.0.0:0 LISTENING TCP 0.0.0.0:445 0.0.0.0:0 LISTENING TCP 0.0.0.0:1029 0.0.0.0:0 LISTENING TCP 0.0.0.0:1036 0.0.0.0:0 LISTENING TCP 0.0.0.0:1078 0.0.0.0:0 LISTENING TCP 0.0.0.0:1080 0.0.0.0:0 LISTENING TCP 0.0.0.0:1086 0.0.0.0:0 LISTENING TCP 0.0.0.0:6515 0.0.0.0:0 LISTENING TCP 127.0.0.1:139 0.0.0.0:0 LISTENING UDP 0.0.0.0:445 *:* UDP 0.0.0.0:1038 *:* UDP 0.0.0.0:6514 *:* UDP 0.0.0.0:6515 *:* UDP 127.0.0.1:1108 *:* UDP 223.223.223.96:500 *:* UDP 223.223.223.96:4500 *:*


Windows XP, this laptop Proto Local Address Foreign Address State TCP ches-pc:epmap ches-pc:0 LISTENING TCP ches-pc:microsoft-ds ches-pc:0 LISTENING TCP ches-pc:1025 ches-pc:0 LISTENING TCP ches-pc:1036 ches-pc:0 LISTENING TCP ches-pc:3115 ches-pc:0 LISTENING TCP ches-pc:3118 ches-pc:0 LISTENING TCP ches-pc:3470 ches-pc:0 LISTENING TCP ches-pc:3477 ches-pc:0 LISTENING TCP ches-pc:5000 ches-pc:0 LISTENING TCP ches-pc:6515 ches-pc:0 LISTENING TCP ches-pc:netbios-ssn ches-pc:0 LISTENING TCP ches-pc:3001 ches-pc:0 LISTENING TCP ches-pc:3002 ches-pc:0 LISTENING TCP ches-pc:3003 ches-pc:0 LISTENING TCP ches-pc:5180 ches-pc:0 LISTENING UDP ches-pc:microsoft-ds *:* UDP ches-pc:isakmp *:* UDP ches-pc:1027 *:* UDP ches-pc:3008 *:* UDP ches-pc:3473 *:* UDP ches-pc:6514 *:* UDP ches-pc:6515 *:* UDP ches-pc:netbios-ns *:* UDP ches-pc:netbios-dgm *:* UDP ches-pc:1900 *:* UDP ches-pc:ntp *:* UDP ches-pc:1900 *:* UDP ches-pc:3471 *:*


FreeBSD partition, this laptop

Active Internet connections (including servers)Proto Recv-Q Send-Q Local Address Foreign Address (state)tcp4 0 0 *.22 *.* LISTENtcp6 0 0 *.22 *.* LISTEN

81 slides

XP SP2

Bill Gets It


Microsoft’s Augean Stables:a task for Hercules

• 3000 oxen, 30 years, that’s roughly one oxen-day per line of code in Windows

• It’s been getting worse since Windows 95


XP SP2: Bill gets it

• “a feature you don’t use should not be a security problem for you.”

• “Security by design”– Too late for that, its all retrofitting now

• “Security by default”– No network services on by default

• Security control panel– Many things missing from it– Speaker could not find ActiveX security settings

• There are a lot of details that remain to be seen.


Microsoft really means it about improving their security

• Their security commitment appears to be real

• It is a huge job

• Opposing forces are unclear to me

• It’s been a long time coming, and frustrating


Microsoft secure client arms race

• We are likely to win, but it is going to be a while


Ches’s wish list

• browsersandbox.org– Uses a .conf file, supplied with browser– Same .conf file for any major OS– Sandbox is impenetrable, no matter what

• I know people have offered solutions for ten years

• I need portability: Linux, FreeBSD, maybe even MSFT, which needs sand boxing in their OS.


Ches’s wish list(cont.)

• Self-jailing samba

• Self-jailing apache


Ches’s wish list(cont.)

• USB “key” for every computer

• No big investment for centralized servers

• Open source interface

• Business model: the dongle hardware, not the servers and software– Atalla had this in 1988!

• Different key for system administrator

• Software that doesn’t abuse admin permission– I.e. least privilege


Conclusions

• Computers are still like my Olds ’88

• They ought to stay that way, to foster creativity and alternatives

• I think we will be getting better, over all

81 slides

40 Years of Internet Arms Races

Bill Cheswick

[email protected]

http://www.lumeta.com

81 slides 40 Years of Internet Arms Races… Bill Cheswick [email protected] .

Documents

Transcript of 81 slides 40 Years of Internet Arms Races… Bill Cheswick [email protected] .