25-SEPT-2001 1

Security Fundamentals

Robin Anderson

UMBC, Office of Information Technology

25-SEPT-2001 2

A Little About Me…

Unix SysAdmin, Specialist with the Office of Information Technology at UMBC

Taught Unix Administration and SANS Level One Security courses at UMBC

Certified by the SANS Institute GIAC program in UNIX Security and Incident Handling

25-SEPT-2001 3

Topics Outline

Post-Mortems in the News… Identifying Threats Countering Threats The (Vulnerable) Network Questions You Need to Ask Recommendations You Want to Make Resources Online

25-SEPT-2001 4

What Happened to Amazon®?

Website defacing: Hackers broke in & put up phony web pages

(And now, newer worms/viruses are doing the same!)

– September 2000: OPEC 1

– February 2000: Amazon® , eBay® 2

– November 1999: NASA/Goddard 3

– October 31,1999: Associated Press® 4

– August 1999: ABC® 5

– June 1999: U.S. Army

25-SEPT-2001 5

What Happened to Yahoo®?

Denial of Service (DoS)– February 2000: Yahoo and CNN 1

Multiple Hits– September 2000: Slashdot defaced– May 2000: Slashdot suffered DoS

The irony is that slashdot.org is a popular "news for nerds" website

25-SEPT-2001 6

If They’re Vulnerable…

…then you are, too.

25-SEPT-2001 7

The Fundamental Theorem

You have computers because they perform some function that furthers your organization’s goals

If you lose the use of those computers, their function is compromised

So - anything that interferes with your organization’s effort to achieve its goals is a security concern

25-SEPT-2001 8

What Are You Protecting?

Information

Availability of the Systems

Reputation & Goodwill

25-SEPT-2001 9

Your Information

Crown Jewels– Trade secrets, patent ideas, research

Financial information

Personnel records

Organizational structure

25-SEPT-2001 10

Your Availability

Internal use– When employees can’t use the network,

servers, or other necessary systems, they can’t work

Website / online transactions– Often when systems are unavailable, the

organization is losing money

25-SEPT-2001 11

Your Reputation

Public trust– If your organization is hacked, how reliable

will people think you are you in other areas?– Who wants to do business with companies that

leak credit card information?

Being a good neighbor– Your organization may be hacked so it can be

used as a springboard to attack others

25-SEPT-2001 12

A Simple Network…

Internet

RouterFirewall

Router

25-SEPT-2001 13

… Attacked!

Internet

RouterFirewall

Router

79

8

1

6

5

4

3

2

10

25-SEPT-2001 14

What Are These Threats?

1. DoS coming from the Internet

2. Severed Physical link

3. Masquerader / Spoofer– They look like they’re already inside

4. Password sniffer

25-SEPT-2001 15

What Are These Threats? (2)

5. Alan brought a floppy from home that has a virus on it

6. Beatrice is about to be fired – and she’s going to be angry about it

7. Carter is careless with his passwords – he writes them down and loses the paper

25-SEPT-2001 16

What Are These Threats? (3)

8. David has unprotected shares on his NT box

9. Evan installed a modem on his PC (PCAnywhere)

10. Severed Power / HVAC

25-SEPT-2001 17

What Are Threat Vectors?

Vectors are the pathways by which threats enter your network

25-SEPT-2001 18

Threat Vectors - Internal

Careless employees– “Floyd the clumsy janitor”– “Contraband” hardware / software – “Oops, did I just type that?”

Random twits (somewhere between careless & malicious)

Malicious employees– Current or former employees with axes to grind

Anyone who can get physical access

25-SEPT-2001 19

Threat Vectors - External

Competitors / spies / saboteurs Casual & incidental hackers

– Some hackers don’t want your systems except to use them to get at their real target

Malicious hackers Accidental tourists Natural disasters

– Be ready to face down the hurricane

25-SEPT-2001 20

What Are Threat Categories?

Categories are the different kinds of threat you may encounter

25-SEPT-2001 21

Threat Categories

Opportunistic– Basic “ankle biters” and “script kiddies”– More advanced hackers, hacker groups out

trolling Targeted

– These attackers know what they want; anything from data to disruption to springboards

“Omnipotent”– Government-sponsored professional hackers

25-SEPT-2001 22

Threat Consequences Bad press

– Breach of confidentiality• Medical data• Credit card information

– Attack platform (you’ve been subverted!)

Loss of income– How much does it cost you in sales to have your

databases, website, etc, down for any given length of time?

– Loss of trade secrets (crown jewels)

25-SEPT-2001 23

The 3 Goals of Security

Ensure Availability

Ensure Integrity

Ensure Authorization & Authentication

25-SEPT-2001 24

Threats to Availability

Denial of Service (DoS)– Connection flooding

Destroying data– Hardware failure– Manual deletion– Software agents: virus, trojans

25-SEPT-2001 25

Threats to Integrity

Hardware failure

Software corruption– Buggy software– Improperly terminated programs

Attacker altering data

25-SEPT-2001 26

Threats to Authorization

Attacker stealing data

Lost / Stolen passwords

Information Reconnaissance• Organization information

25-SEPT-2001 27

Countering These Threats…

…is what security is all about.

25-SEPT-2001 28

Defining Security

Security is a process– Training is ongoing

• Threats change, admins need to keep up

• Security is inconvenient, all staff needs training

Security is also about policies There is no silver bullet to fix it all

– For example, a firewall won’t save you• Remember the Maginot Line

25-SEPT-2001 29

Notes:

The underlying assumption in the next section is that you, as the auditor, admin, or manager, are in a position to make security recommendations

The following list of questions should not be considered in any way to be exhaustive, but a starting point to build your own list

25-SEPT-2001 30

Questions You Need to Ask

What is the physical access policy to systems, routers, and backup media?– Are the servers and main routers in a

controlled-access environment?– Who monitors access?

Are desktop systems / workstations physically secured?

25-SEPT-2001 31

Questions You Need to Ask

Is there a documented security policy?– Where is it located?– Who is responsible for maintaining it?– Is the policy being consistently enforced?– Who is the enforcer for the organization?

Is there a firewall?– Who maintains it and its rule-sets?– Do its rules match the policy?

25-SEPT-2001 32

Questions You Need to Ask

What is the backup policy & schedule?

– What kind of backup media & software is used?

– Where is the backup media stored? Is there an off-site safe/storage rotation?

– If the systems were utterly destroyed today, how up to date could you bring their replacements?

– Have the backups ever been tested (via a restore) for completeness and integrity?

25-SEPT-2001 33

Questions You Need to Ask

Does the organization know what is on its network?

– If so, how does it know?– Where are the records kept?– Who has access to them?

25-SEPT-2001 34

Questions You Need to Ask

Are routine network vulnerability scans run?– If so, what tools are used?

– Where are the reports stored?

– Who has access to the tool and the reports?

Is any routine network monitoring done?– If so, what tools are used?

– Where are the reports stored?

– Who has access to the tool and the reports?

25-SEPT-2001 35

Questions You Need to Ask

What kind of power management contingencies are available?

– Uninterruptible Power Supplies (UPS)?– Power regulation?– Backup generators? – Mean time to recovery from outage?

25-SEPT-2001 36

Questions You Need to Ask

What kind of authentication does your organization use?– Passwords

• Multi-use, one-time?

• Expiration?

– Biometric authentication?– Smart-cards

25-SEPT-2001 37

Questions You Need to Ask

If you use passwords, how does your organization replace lost ones?

– Any policy on verifying user’s identity, etc?

25-SEPT-2001 38

Questions You Need to Ask

What kind of network connections does your organization allow?– Are they clear-text protocols (like telnet, rlogin,

rsh, ftp)?– Can your organization migrate to using

encrypted protocols (like ssh, stunnel, etc)?

25-SEPT-2001 39

Recommendations You Really Want to Make No matter what, recommend a dedicated

security officer

– One individual responsible for security• NOT the sys admin, network admin

– Qualifications:• Training• Certification (CISSP, SANS)• Demonstrated proficiency

25-SEPT-2001 40

Recommendations You Really Want to Make

Routine Vulnerability Scanning– Tools like Saint, Nessus, Legion, Nmap, SARA

Principle of Least Privilege

Documented Procedures for Incident Handling

25-SEPT-2001 41

So, What Is a Security Officer?

Protector– Internal, external

Assessor Monitor Contact point

– Law enforcement– Internal– External

25-SEPT-2001 42

What Does It All Mean?

It’s a dangerous world, but we’re not necessarily doomed!

Security is an ongoing process (it’s worth repeating!)

– Ask the questions you’ve seen here– Ask any others you think of– Ask them all again tomorrow – new challenges

are arising every day!

25-SEPT-2001 43

Acknowledgements

Andy Johnston, manager and co-conspirator

Jon Lasser, author of Think UNIX

Stephen Northcutt, SANS instructor and author of Network Intrusion Detection

25-SEPT-2001 44

Resources Online

Training and Certifications

– SANS Institute

http://www.sans.org/

– CISSP “Certification for Information System Security Professional”

http://www.cissps.com

25-SEPT-2001 45

Resources Online (2)

News & Alerts– Security Focus

http://www.securityfocus.com/ – CERT was “Computer Emergency Response Team”

http://www.cert.org/ – CIAC “Computer Incident Advisory Capability”

http://ciac.llnl.gov/

25-SEPT-2001 46

Resources Online (3)

Federal Information Sharing Organizations– NIPC “National Infrastructure Protection Center”

http://www.nipc.gov– Infragard “Guarding the Nation’s Infrastructure”

http://www.infragard.net

– Infragard Maryland Chapter

http://www.mdinfragard.org

25-SEPT-2001 47

Resources Online (4) SSH

http://www.ssh.fi http://www.openssh.org

SSH tunnelhttp://linuxdoc.org/HOWTO/mini/VPN.html http://www.ccs.neu.edu/groups/systems/howto/howto-sshtunnel.html

Stunnelhttp://mike.daewoo.com.pl/computer/stunnel/http://www.stanton.dtcc.edu/stanton/cs/admin/notes/ssl/

25-SEPT-2001 48

Resources Online (5)

Network Monitoring Software– Snort

http://www.snort.org

Network Vulnerability Scanners– Saint

http://wdsilx.wwdsi.com/saint – Nessus

http://www.nessus.org

25-SEPT-2001 49

Resources Online (6)

Kerberoshttp://web.mit.edu/kerberos/www

This Presentationhttp://www.gl.umbc.edu/~robin/security.html