Transcript Ch10aProtectionMechanisms

INFORMATION SECURITY
MANAGEMENT
LECTURE 9: PROTECTION MECHANISMS
You got to be careful if you don’t know where you’re going,
because you might not get there. – Yogi Berra
Hacking Networks
Phase 1: Reconnaissance
 Physical Break-In
 Dumpster Diving
 Google, Newsgroups,
Web sites
 Social Engineering


Phishing: fake email
Pharming: fake web
pages
 WhoIs Database
 Domain Name Server
Interrogations
Registrant:
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
US
Domain name: MICROSOFT.COM
Administrative Contact:
Administrator, Domain [email protected]
One Microsoft Way
Redmond, WA 98052
US
+1.4258828080
Technical Contact:
Hostmaster, MSN [email protected]
One Microsoft Way
Redmond, WA 98052 US
+1.4258828080
Registration Service Provider:
DBMS VeriSign, [email protected]
800-579-2848 x4
Please contact DBMS VeriSign for domain updates,
DNS/Nameserver
changes, and general domain support questions.
Registrar of Record: TUCOWS, INC.
Record last updated on 27-Aug-2006.
Record expires on 03-May-2014.
Record created on 02-May-1991.
Domain servers in listed order:
NS3.MSFT.NET 213.199.144.151
NS1.MSFT.NET 207.68.160.190
NS4.MSFT.NET 207.46.66.126
NS2.MSFT.NET 65.54.240.126
NS5.MSFT.NET 65.55.238.126
Hacking Networks
Phase 2: Scanning
War Driving: Can I find a wireless network?
War Dialing: Can I find a modem to connect to?
Network Mapping: What IP addresses exist, and what
ports are open on them?
Vulnerability-Scanning Tools: What versions of
software are implemented on devices?
Passive Attacks
Eavesdropping: Listen to packets from other
parties = Sniffing
Traffic Analysis: Learn about network from
observing traffic patterns
Footprinting: Test to determine software
installed on system = Network Mapping
Hacking Networks:
Phase 3: Gaining Access
Network Attacks:
 Sniffing
(Eavesdropping)
 IP Address Spoofing
 Session Hijacking
System Attacks:
 Buffer Overflow
 Password Cracking
 SQL Injection
 Web Protocol Abuse
 Denial of Service
 Trap Door
 Virus, Worm, Trojan
horse,
Some Active Attacks
Denial of Service: Message did not make it; or
service could not run
Masquerading or Spoofing: The actual sender is not
the claimed sender
Message Modification: The message was modified
in transmission
Packet Replay: A past packet is transmitted again in
order to gain access or otherwise cause damage
Man-in-the-Middle Attack
10.1.1.1
10.1.1.3
(2) Login
(1) Login
(4) Password
(3) Password
10.1.1.2
Hacking Networks:
Phase 4: Exploit/Maintain Access
Control system:
system commands,
log keystrokes, pswd
Backdoor
Trojan Horse
Useful utility actually
creates a backdoor.
Replaces system
User-Level Rootkit executables: e.g.
Login, ls, du
Bots
Slave forwards/performs
commands; spreads,
list email addrs, DOS
attacks
Spyware/Adware
Spyware: Collect info:
keystroke logger,
collect credit card #s,
AdWare: insert ads,
filter search results
Replaces OS kernel:
Kernel-Level e.g. process or file
Rootkit
control to hide
Botnets
Botnets: Bots
Attacker
China
Handler
Hungary
Bots: Host illegal movies,
music, pornography,
criminal web sites, …
Forward Spam for
financial gain
Zombies
Distributed Denial of Service
Zombies
Attacker
Russia
Handler
Victim
Bulgaria
United
States
Can barrage a victim
server with requests,
causing the network
to fail to respond to anyone
Zombies
Introduction
• Threats -> Vulnerabilities -> Risk ->Controls
• Technical controls
–
Must be combined with sound policy and
education, training, and awareness efforts
• Examples of technical security mechanisms
Sphere of Protection
Management of Information Security, 3rd ed.
Source: Course Technology/Cengage Learning
Access Controls
• The four processes of access control
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Identification
Authentication
Authorization
Accountability
• A successful access control approach always
incorporates all four of these elements
Access Controls – Password Strength
Table 10-1 Password power
Source: Course Technology/Cengage Learning
Acceptability of Biometrics
•
Note: Iris Scanning has experienced rapid growth in popularity and
due to it’s acceptability, low cost, and effective security
Google Offers New Alternative for Biometrics
Firewalls
• Any device that prevents a specific type of
information from moving between two
networks
Types:
•
•
•
Packet Filtering
Application Level
Stateful Inspection Firewalls
The Development of Firewalls
• Packet filtering firewalls
–
Simple networking devices that filter packets by
examining every incoming and outgoing packet
header
The Development of Firewalls
• Packet filtering firewalls
The Development of Firewalls
• Application-level firewalls
–
Consists of dedicated computers kept separate
from the first filtering router (edge router)
–
Commonly used in conjunction with a second or
internal filtering router - or proxy server
–
Implemented for specific protocols
The Development of Firewalls
• Application-level firewalls
The Development of Firewalls
• Stateful inspection firewalls
–
Keeps track of each network connection
established between internal and external
systems using a state table
–
Can restrict incoming packets by allowing
access only to packets that constitute
responses to requests from internal hosts
Firewall
Configurations
terminal
host
firewall
A
A
terminal
host
firewall
A
A
A
Router Packet Filtering:
Packet header is inspected
Single packet attacks caught
Very little overhead in firewall: very quick
High volume filter
Stateful Inspection
State retained in firewall memory
Most multi-packet attacks caught
More fields in packet header inspected
Little overhead in firewall: quick
Firewall
Configurations
terminal
host
firewall
A
B
A B
Application-Level Firewall
Packet session terminated and recreated
via a Proxy Server
Packet header completely inspected
Most or all of application inspected
Highest overhead: slow & low volume
Firewall Architectures
• Each firewall generation can be implemented
in several architectural configurations
• Common architectural implementations
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Packet filtering routers
Screened-host firewalls
Dual-homed host firewalls
Screened-subnet firewalls
Firewall Architectures:
Packet filtering routers
Most organizations with an Internet connection
use some form of router between their internal
networks and the external service provider
Firewall Architectures:
Screened-host firewall systems
• Combine the packet filtering router with a separate,
dedicated firewall such as an application proxy
server
Firewall Architectures:
Dual-Homed host firewalls
• The bastion host contains two network interfaces
1. One is connected to the external network
2. One is connected to the internal network
Selecting the Right Firewall
• Firewall Technology
• Cost
• Maintenance
• Future Growth
Managing Firewalls
• Any firewall device must have its own configuration
• Firewall Rules
• Policy regarding firewall use
Managing Firewalls (cont’d.)
• Firewall best practices
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All traffic from the trusted network allowed out
The firewall is never accessible directly from the
public network
Email Policies
Intrusion Detection and
Prevention Systems (IDPS)
• The term intrusion detection/prevention
system (IDPS) can be used to describe
current anti-intrusion technologies
• Like firewall systems, IDPSs require complex
configurations to provide the level of
detection and response desired
Intrusion Detection and Prevention
Systems (cont’d.)
 IDPS technologies can respond to a detected
threat by attempting to prevent it from
succeeding
 Different Response Techniques

IDS vs. IPS
 Network or Host Based Protection
IDPS – Host vs. Network
http://www.windowsecurity.com/articles-tutorials/intrusion_detection/Hids_vs_Nids_Part1.html
Intrusion Detection Systems (IDS)
Intrusion Prevention Systems (IPS)
Router
IDS
Firewall
Network IDS=NIDS
 Examines packets for attacks
 Can find worms, viruses, orgdefined attacks
 Warns administrator of attack
 IPS=Packets are routed
through IPS
Host IDS=HIDS
 Examines actions or resources
for attacks
 Recognize unusual or
inappropriate behavior
 E.g., Detect modification or
deletion of special files
Signature-Based IDPS
• Examines data traffic for something that
matches the preconfigured, predetermined
attack pattern signatures
• Weakness: slow and methodical attacks may
slip undetected through the IDPS, as their
actions may not match a signature that includes
factors based on duration of the events
Statistical Anomaly-Based IDPS
• First collects data from normal traffic and
establishes a baseline
–
Then periodically samples network activity, based
on statistical methods, and compares the
samples to the baseline
• Advantage: Able to detect new types of attacks,
because it looks for abnormal activity of any type
Managing Intrusion Detection and
Prevention Systems
• IDPSs must be configured to differentiate
between routine circumstances and low,
moderate, or severe threats
• A properly configured IDPS can translate a
security alert into different types of notifications
• Most IDPSs monitor systems using agents
• Consolidated enterprise manager
Honeypot & Honeynet
Honeypot: A system with a special software application
which appears easy to break into
Honeynet: A network which appears easy to break into
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Purpose: Catch attackers
All traffic going to honeypot/net is suspicious
If successfully penetrated, can launch further attacks
Must be carefully monitored
Firewall
Honey
Pot
External
DNS
IDS
Web
Server
E-Commerce
VPN
Server
Remote Access Protection
• Network connectivity using external connections
–
Usually much simpler and less sophisticated than
Internet connections
–
Simple user name and password schemes are
usually the only means of authentication
RADIUS and TACACS
• Systems that authenticate the credentials of dial-
up access users
• Typical dial-up systems place the authentication
of users on the system connected to the modems
• Options:
• Remote Authentication Dial-In User Service (RADIUS)
• Terminal Access Controller Access Control(TACACS)
Authentication Protocols
 RADIUS

Over-the-wire protocol from client
to AAA (authentication, authorization,
accounting) server
 TACACS
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Between access point or gateway and
an AAA server
Replaced by TACACS+ and RADIUS
RADIUS and TACACS (cont’d.)
Source: Course Technology/Cengage Learning
Managing Connections
• Organizations that continue to offer remote
access must:
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Determine how many connections the
organization has
Control access to authorized modem numbers
Use call-back whenever possible
Use token-based authentication if at all
possible
Wireless Networking Protection
• Use IEEE 802.11 protocol
• War driving
–
Moving through a geographic area or building,
actively scanning for open or unsecured WAPs
• Common encryption protocols used to secure
wireless networks
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Wired Equivalent Privacy (WEP)
Wi-Fi Protected Access (WPA)
Wired Equivalent Privacy (WEP)
• Provides a basic level of security to prevent
unauthorized access or eavesdropping
• Fundamental Cryptological Flaws
–
Resulting in vulnerabilities that can be exploited,
which led to replacement by WPA
Wi-Fi Protected Access (WPA)
• WPA is an industry standard
• IEEE 802.11i
–
Has been implemented in products such as
WPA2

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WPA2 has newer, more robust security protocols
based on the Advanced Encryption Standard
WPA /WPA 2 provide increased capabilities
for authentication, encryption, and throughput
Managing Wireless Connections
• Regulate the wireless network footprint
• Select WPA or WPA2 over WEP
• Protect preshared keys
Wi-Fi security
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SSID should be a non-default value
SSID broadcast should be disabled
MAC access control
Authentication
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Require ID and password, may use a RADIUS
server
Encryption
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WEP (Wired Equivalent Privacy)
WPA (Wireless Protected Access)
WPA2 (superset of WPA, full standard
PSK v. RADIUS
 WPA and WPA-2 operate in two modes
 Pre-Shared Key (PSK)
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Users must enter the key on each device
 RADIUS server
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Used with 802.1x authentication
Each user has an individual key
More secure, recommended for enterprises
Scanning and Analysis Tools
• Used to find vulnerabilities in systems
• Security administrators may use attacker’s
tools to examine their own defenses and
search out areas of vulnerability
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•
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Scanning tools
Footprinting
Fingerprinting
Port Scanners
• Port scanning utilities (port scanners)
Vulnerability Scanners
• Capable of scanning networks for very
detailed information
• Identify exposed user names and groups,
show open network shares, and expose
configuration problems and other server
vulnerabilities
http://www.tenable.com/products/nessus
Packet Sniffers
• A network tool that collects and analyzes
packets on a network
• Connects directly to a local network from an
internal location
http://www.wireshark.org/
Content Filters
• A software program or a hardware/software
appliance that allows administrators to restrict
content that comes into a network
• Common application of a content filter
–
Restriction of access to Web sites with nonbusiness-related material, such as
pornography, or restriction of spam e-mail
Examples of Content Filters
Trap and Trace
• Trap
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Describes software designed to entice
individuals who are illegally perusing the
internal areas of a network
• Trace
–
A process by which the organization attempts
to determine the identity of someone
discovered in unauthorized areas of the
network or systems
Managing Scanning and Analysis
Tools
• The security manager must be able to see
the organization’s systems and networks from
the viewpoint of potential attackers
Managing Scanning and Analysis
Tools (cont’d.)
• Drawbacks:
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Tools do not have human-level capabilities
Most tools function by pattern recognition, so
they only handle known issues
Most tools are computer-based, so they are
prone to errors, flaws, and vulnerabilities of
their own
Tools are designed, configured, and operated
by humans and are subject to human errors
Managing Scanning and Analysis
Tools (cont’d.)
• Drawbacks: (cont’d.)
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Some governments, agencies, institutions,
and universities have established policies or
laws that protect the individual user’s right to
access content
Tool usage and configuration must comply
with an explicitly articulated policy, and the
policy must provide for valid exceptions