KEMBAR78
640-554 IT Certification and Career Paths | PPTX
Network Security
• Types of Attacks
• Attacks on the OSI & TCP/IP Model
• Attack Methods
• Prevention
• Switch Vulnerabilities and Hacking
• Cisco Routers
• Interesting links
Objectives
Trish Miller
• Physical Access
Attacks
– Wiretapping
– Server Hacking
– Vandalism
• Dialog Attacks
– Eavesdropping
– Impersonation
– Message Alteration
Types of Attacks
Trish Miller
• Social Engineering
– Opening Attachments
– Password Theft
– Information Theft
Types of Attacks (Cont.)
• Penetration Attacks
– Scanning (Probing)
– Break-in
– Denial of Service
– Malware
• Viruses
• Worms
Risk Analysis of the Attack
• What is the cost if the attack succeeds?
• What is the probability of occurrence?
• What is the severity of the threat?
• What is the countermeasure cost?
• What is the value to protect the system
• Determine if the countermeasure should be
implemented.
• Finally determine its priority.
OSI & TCP/IP Related
Attacks
• Session
– Password theft
– Unauthorized Access
with Root permission
• Transport & Network:
– Forged TCP/IP
addresses
– DoS Attacks
OSI Model Related Attacks
• Application layer:
– Attacks on web
– Attacks are typically
virus
• Presentation:
– Cracking of encrypted
transmissions by short
encryption key
• Data Link &
Physical
– Network Sniffers
– Wire Taps
– Trojan Horses
– Malicious code
OSI Model Related Attacks
Attacks Related to TCP Packet
• Port Number
– Applications are identified by their Port
numbers
– Well-known ports (0-1023)
• HTTP=80, Telnet=23, FTP=21 for supervision,
20 for data transfer, SMTP=25
– Allows applications to be accessed by the
root user
• IP address spoofing
– Change the source IP address
– To conceal identity of the attacker
– To have the victim think the packet comes
from a trusted host
– LAND attack
Attacks Related to TCP Packet
Attacks Related to TCP Packet
• Port Number
– Registered ports (1024-49152) for any
application
– Not all operating systems uses these port
ranges, although all use well-known ports
Attack Methods
• Host Scanning
• Network Scanning
• Port Scanning
• Fingerprinting
Attack Methods
• Host Scanning
– Ping range of IP addresses or use
alternative scanning messages
– Identifies victims
– Types of Host scanning
• Ping Scanning
• TCP SYN/ACK attacks
Attack Methods (Cont.)
• Network Scanning
– Discovery of the network infrastructure
(switches, routers, subnets, etc.)
– Tracert and applications similar identifies all
routers along the route to a destination host
Attack Methods (Cont.)
• Port Scanning
– Once a host is identified, scan all ports to find
out if it is a server and what type it is
– Two types:
• Server Port Scanning
– TCP
– UDP
• Client Port Scanning
– NetBIOS
– Ports 135 – 139 used for NetBIOS ports used for file
and print services.
– GRC.com a free website that scan your pc for open
ports.
Attack Methods (Cont.)
• Fingerprinting
– Discovers the host operating system and
applications as well as the version
• Active (sends)
• Passive (listen)
– Nmap does all major scanning methods
Attack Methods (Cont.)
• Denial-of-Service (DoS) Attacks
– Attacks on availability
– SYN flooding attacks overload a host or
network with connection attempts
– Stopping DoS attacks is very hard.
Attack Methods (Cont.)
• The Break-In
– Password guessing
– Take advantage of unpatched vulnerabilities
– Session hijacking
Attack Methods (Cont.)
• Download rootkit via TFTP
• Delete audit log files
• Create backdoor account or Trojan
backdoor programs
After the Compromise
• Weaken security
• Access to steal information, do
damage
• Install malicious software (RAT, DoS
zombie, spam relay, etc.)
After the Compromise (Cont.)
Prevention
Preventions
• Stealth Scanning
• Access Control
• Firewalls
• Proxy Servers
• IPsec
• Security Policies
• DMZ
• Host Security
• Noisiness of Attacks
• Exposure of the Attacker’s IP Address
• Reduce the rate of Attack below the IDS
Threshold
• Scan Selective Ports
Stealth Scanning
• The goal of access control is to prevent
attackers from gaining access, and stops them if
they do.
• The best way to accomplish this is by:
– Determine who needs access to the resources
located on the server.
– Decide the access permissions for each resource.
– Implement specific access control policies for each
resource.
– Record mission critical resources.
– Harden the server against attacks.
– Disable invalid accounts and establish policies
Access Control
Firewalls
• Firewalls are designed to protect
you from outside attempts to
access your computer, either for
the purpose of eavesdropping on
your activities, stealing data,
sabotage, or using your machine as
a means to launch an attack on a
third party.
Firewalls (Cont.)
• Hardware
– Provides a strong degree of
protection from the outside
world.
– Can be effective with little or no
setup
– Can protect multiple systems
• Software
– Better suite to protect against
Trojans and worms.
– Allows you to configure the ports
you wish to monitor. It gives you
more fine control.
– Protects a single system.
Firewalls
• Can Prevent
– Discovery
• Network
• Traceroute
– Penetration
• Synflood
• Garbage
• UDP Ping
• TCP Ping
• Ping of Death
Proxy
• A proxy server is a buffer between your network and the
outside world.
• Use an anonymous Proxy to prevent attacks.
IPSec
• Provides various security services for traffic at
the IP layer
• These security services include
– Authentication
– Integrity
– Confidentiality
IPsec overview - how IPsec helps
Problem How IPsec
helps
Details
Unauthorized
system access
Authentication,
tamperproofing
Defense in depth by isolating
trusted from untrusted
systems
Targeted
attacks of high-
value servers
Authentication,
tamperproofing
Locking down servers with
IPsec. Examples: HR
servers, Outlook® Web
Access (OWA), DC
replication
Eavesdropping Authentication,
confidentiality
Defense in depth against
password or information
gathering by untrusted
systems
Government
guideline
compliance
Authentication,
confidentiality
Example: “All
communications between
financial servers must be
encrypted.”
DMZ Image
• Hardening Servers
• Cisco IOS
• Upgrades and Patches
• Unnecessary Services
• Network Monitoring tools
Host Security
Switch Vulnerabilities and
Hacking
• Used to locate IP address, version, and
model.
• Mass amounts of packets being sent can
fake a crash
• Used to troubleshoot network, but should
be disabled.
CDP Protocol
• Give users data by poisoning ARP cache
of end node.
• MAC address used to determine
destination. Device driver does not check.
• User can forge ARP datagram for man in
the middle attack.
ARP Poisoning
• SNMP manages the network.
• Authentication is weak. Public and
Private community keys are clear text.
• Uses UDP protocol which is prone to
spoofing.
• Enable SNMPv3 without backwards
compatibility.
SNMP
• Standard STP takes 30-45 seconds to
deal with a failure or Root bridge
change.
• Purpose: Spanning Tree Attack reviews
the traffic on the backbone.
Spanning Tree Attacks
Trish Miller
• Only devices affected by the failure
notice the change
• The attacker can create DoS condition
on the network by sending BPDUs
from the attacker.
Spanning Tree Attacks
• STEP 1: MAC flood the access switch
• STEP 2: Advertise as a priority zero
bridge.
Spanning Tree Attacks (Cont.)
Spanning Tree Attacks (Cont.)
• STEP 3: The attacker becomes the
Root bridge!
– Spanning Tree recalculates.
– The backbone from the original network is
now the backbone from the attacking host
to the other switches on the network.
Spanning Tree Attacks (Cont.)
• Disabling STP can introduce
another attack.
• BPDU Guard
– Disables ports using portfast upon
detection of a BPDU message on
the port.
– Enabled on any ports running
portfast
STP Attack Prevention
• Root Guard
– Prevents any ports that can become the
root bridge due to their BPDU
STP Attack Prevention
• Cisco Content Switching Modules
• Cisco Content Switching Module with
SSL
CSM and CSM-S
• Cisco Secure Desktop
– 3 major vulnerabilities
• Maintains information after an Internet
browsing session. This occurs after an SSL
VPN session ends.
• Evades the system via the system policies
preventing logoff, this will allow a VPN
connection to be activated.
• Allow local users to elevate their privileges.
CDM
Trish Miller
• Prevention
– Cisco has software to address the
vulnerabilities.
– There are workarounds available to mitigate
the effects of some of these vulnerabilities.
Cisco Routers
• Two potential issues with Cisco
Routers
– Problems with certain IOS software
– SNMP
Cisco Routers
• Devices running Cisco IOS versions
12.0S, 12.2, 12.3 or 12.4
– Problem with the software
– Confidential information can be leaked out
– Software updates on the CISCO site can fix
this problem
•Virtual Private Networks
Virtual connection 1
Virtual Connection 2
Trish Miller
•Virtual Private Networks
Information leak
Error
Connection
• Cisco uBR10012 series devices automatically
enable SNMP read/write access
• Since there are no access restrictions on this
community string , attackers can exploit this to
gain complete control of the device
CISCO
Router
Attacking
Computer
By sending an SNMP set request with a spoofed source IP address
the attacker will be able to get the Victim router to send him its
configuration file.
CISCO
Router
Attacking
Computer
With this information, the remote computer will be able to
have complete control over this router
• Fixes- Software updates available on
the CICSO site that will fix the
Read/Write problem
Links
• http://sectools.org/tools2.html
• http://insecure.org/sploits/l0phtcrack.lanman.problems.html
• http://www.testbells.com/
• http://www.examcollectionvce.com/
• http://www.hidemyass.com/
References
• http://www.bmighty.com/network/showArticle.jhtml;jsessionid=2YYDWJHHX3
FL2QSNDLPSKHSCJUNN2JVN?articleID=202401432&pgno=2
• http://www.juniper.net/security/auto/vulnerabilities/vuln19998.html
• http://www.blackhat.com/presentations/bh-usa-02/bh-us-02-convery-
switches.pdf
• http://www.askapache.com/security/hacking-vlan-switched-networks.html
• http://marc.info/?l=bugtraq&m=116300682804339&w=2
• http://www.secureroot.com/security/advisories/9809702147.html
640-554 IT Certification and Career Paths

640-554 IT Certification and Career Paths

  • 1.
  • 2.
    • Types ofAttacks • Attacks on the OSI & TCP/IP Model • Attack Methods • Prevention • Switch Vulnerabilities and Hacking • Cisco Routers • Interesting links Objectives
  • 3.
    Trish Miller • PhysicalAccess Attacks – Wiretapping – Server Hacking – Vandalism • Dialog Attacks – Eavesdropping – Impersonation – Message Alteration Types of Attacks
  • 4.
    Trish Miller • SocialEngineering – Opening Attachments – Password Theft – Information Theft Types of Attacks (Cont.) • Penetration Attacks – Scanning (Probing) – Break-in – Denial of Service – Malware • Viruses • Worms
  • 5.
    Risk Analysis ofthe Attack • What is the cost if the attack succeeds? • What is the probability of occurrence? • What is the severity of the threat? • What is the countermeasure cost? • What is the value to protect the system • Determine if the countermeasure should be implemented. • Finally determine its priority.
  • 6.
    OSI & TCP/IPRelated Attacks
  • 7.
    • Session – Passwordtheft – Unauthorized Access with Root permission • Transport & Network: – Forged TCP/IP addresses – DoS Attacks OSI Model Related Attacks • Application layer: – Attacks on web – Attacks are typically virus • Presentation: – Cracking of encrypted transmissions by short encryption key
  • 8.
    • Data Link& Physical – Network Sniffers – Wire Taps – Trojan Horses – Malicious code OSI Model Related Attacks
  • 9.
    Attacks Related toTCP Packet • Port Number – Applications are identified by their Port numbers – Well-known ports (0-1023) • HTTP=80, Telnet=23, FTP=21 for supervision, 20 for data transfer, SMTP=25 – Allows applications to be accessed by the root user
  • 10.
    • IP addressspoofing – Change the source IP address – To conceal identity of the attacker – To have the victim think the packet comes from a trusted host – LAND attack Attacks Related to TCP Packet
  • 11.
    Attacks Related toTCP Packet • Port Number – Registered ports (1024-49152) for any application – Not all operating systems uses these port ranges, although all use well-known ports
  • 12.
  • 13.
    • Host Scanning •Network Scanning • Port Scanning • Fingerprinting Attack Methods
  • 14.
    • Host Scanning –Ping range of IP addresses or use alternative scanning messages – Identifies victims – Types of Host scanning • Ping Scanning • TCP SYN/ACK attacks Attack Methods (Cont.)
  • 15.
    • Network Scanning –Discovery of the network infrastructure (switches, routers, subnets, etc.) – Tracert and applications similar identifies all routers along the route to a destination host Attack Methods (Cont.)
  • 16.
    • Port Scanning –Once a host is identified, scan all ports to find out if it is a server and what type it is – Two types: • Server Port Scanning – TCP – UDP • Client Port Scanning – NetBIOS – Ports 135 – 139 used for NetBIOS ports used for file and print services. – GRC.com a free website that scan your pc for open ports. Attack Methods (Cont.)
  • 17.
    • Fingerprinting – Discoversthe host operating system and applications as well as the version • Active (sends) • Passive (listen) – Nmap does all major scanning methods Attack Methods (Cont.)
  • 18.
    • Denial-of-Service (DoS)Attacks – Attacks on availability – SYN flooding attacks overload a host or network with connection attempts – Stopping DoS attacks is very hard. Attack Methods (Cont.)
  • 19.
    • The Break-In –Password guessing – Take advantage of unpatched vulnerabilities – Session hijacking Attack Methods (Cont.)
  • 20.
    • Download rootkitvia TFTP • Delete audit log files • Create backdoor account or Trojan backdoor programs After the Compromise
  • 21.
    • Weaken security •Access to steal information, do damage • Install malicious software (RAT, DoS zombie, spam relay, etc.) After the Compromise (Cont.)
  • 22.
  • 23.
    Preventions • Stealth Scanning •Access Control • Firewalls • Proxy Servers • IPsec • Security Policies • DMZ • Host Security
  • 24.
    • Noisiness ofAttacks • Exposure of the Attacker’s IP Address • Reduce the rate of Attack below the IDS Threshold • Scan Selective Ports Stealth Scanning
  • 25.
    • The goalof access control is to prevent attackers from gaining access, and stops them if they do. • The best way to accomplish this is by: – Determine who needs access to the resources located on the server. – Decide the access permissions for each resource. – Implement specific access control policies for each resource. – Record mission critical resources. – Harden the server against attacks. – Disable invalid accounts and establish policies Access Control
  • 26.
    Firewalls • Firewalls aredesigned to protect you from outside attempts to access your computer, either for the purpose of eavesdropping on your activities, stealing data, sabotage, or using your machine as a means to launch an attack on a third party.
  • 27.
    Firewalls (Cont.) • Hardware –Provides a strong degree of protection from the outside world. – Can be effective with little or no setup – Can protect multiple systems • Software – Better suite to protect against Trojans and worms. – Allows you to configure the ports you wish to monitor. It gives you more fine control. – Protects a single system.
  • 28.
    Firewalls • Can Prevent –Discovery • Network • Traceroute – Penetration • Synflood • Garbage • UDP Ping • TCP Ping • Ping of Death
  • 29.
    Proxy • A proxyserver is a buffer between your network and the outside world. • Use an anonymous Proxy to prevent attacks.
  • 30.
    IPSec • Provides varioussecurity services for traffic at the IP layer • These security services include – Authentication – Integrity – Confidentiality
  • 31.
    IPsec overview -how IPsec helps Problem How IPsec helps Details Unauthorized system access Authentication, tamperproofing Defense in depth by isolating trusted from untrusted systems Targeted attacks of high- value servers Authentication, tamperproofing Locking down servers with IPsec. Examples: HR servers, Outlook® Web Access (OWA), DC replication Eavesdropping Authentication, confidentiality Defense in depth against password or information gathering by untrusted systems Government guideline compliance Authentication, confidentiality Example: “All communications between financial servers must be encrypted.”
  • 32.
  • 33.
    • Hardening Servers •Cisco IOS • Upgrades and Patches • Unnecessary Services • Network Monitoring tools Host Security
  • 34.
  • 35.
    • Used tolocate IP address, version, and model. • Mass amounts of packets being sent can fake a crash • Used to troubleshoot network, but should be disabled. CDP Protocol
  • 36.
    • Give usersdata by poisoning ARP cache of end node. • MAC address used to determine destination. Device driver does not check. • User can forge ARP datagram for man in the middle attack. ARP Poisoning
  • 37.
    • SNMP managesthe network. • Authentication is weak. Public and Private community keys are clear text. • Uses UDP protocol which is prone to spoofing. • Enable SNMPv3 without backwards compatibility. SNMP
  • 38.
    • Standard STPtakes 30-45 seconds to deal with a failure or Root bridge change. • Purpose: Spanning Tree Attack reviews the traffic on the backbone. Spanning Tree Attacks
  • 39.
    Trish Miller • Onlydevices affected by the failure notice the change • The attacker can create DoS condition on the network by sending BPDUs from the attacker. Spanning Tree Attacks
  • 40.
    • STEP 1:MAC flood the access switch • STEP 2: Advertise as a priority zero bridge. Spanning Tree Attacks (Cont.)
  • 41.
    Spanning Tree Attacks(Cont.) • STEP 3: The attacker becomes the Root bridge! – Spanning Tree recalculates. – The backbone from the original network is now the backbone from the attacking host to the other switches on the network. Spanning Tree Attacks (Cont.)
  • 42.
    • Disabling STPcan introduce another attack. • BPDU Guard – Disables ports using portfast upon detection of a BPDU message on the port. – Enabled on any ports running portfast STP Attack Prevention
  • 43.
    • Root Guard –Prevents any ports that can become the root bridge due to their BPDU STP Attack Prevention
  • 44.
    • Cisco ContentSwitching Modules • Cisco Content Switching Module with SSL CSM and CSM-S
  • 45.
    • Cisco SecureDesktop – 3 major vulnerabilities • Maintains information after an Internet browsing session. This occurs after an SSL VPN session ends. • Evades the system via the system policies preventing logoff, this will allow a VPN connection to be activated. • Allow local users to elevate their privileges. CDM
  • 46.
    Trish Miller • Prevention –Cisco has software to address the vulnerabilities. – There are workarounds available to mitigate the effects of some of these vulnerabilities.
  • 47.
  • 48.
    • Two potentialissues with Cisco Routers – Problems with certain IOS software – SNMP Cisco Routers
  • 49.
    • Devices runningCisco IOS versions 12.0S, 12.2, 12.3 or 12.4 – Problem with the software – Confidential information can be leaked out – Software updates on the CISCO site can fix this problem
  • 50.
    •Virtual Private Networks Virtualconnection 1 Virtual Connection 2
  • 51.
    Trish Miller •Virtual PrivateNetworks Information leak Error Connection
  • 52.
    • Cisco uBR10012series devices automatically enable SNMP read/write access • Since there are no access restrictions on this community string , attackers can exploit this to gain complete control of the device
  • 53.
    CISCO Router Attacking Computer By sending anSNMP set request with a spoofed source IP address the attacker will be able to get the Victim router to send him its configuration file.
  • 54.
    CISCO Router Attacking Computer With this information,the remote computer will be able to have complete control over this router
  • 55.
    • Fixes- Softwareupdates available on the CICSO site that will fix the Read/Write problem
  • 56.
    Links • http://sectools.org/tools2.html • http://insecure.org/sploits/l0phtcrack.lanman.problems.html •http://www.testbells.com/ • http://www.examcollectionvce.com/ • http://www.hidemyass.com/
  • 57.
    References • http://www.bmighty.com/network/showArticle.jhtml;jsessionid=2YYDWJHHX3 FL2QSNDLPSKHSCJUNN2JVN?articleID=202401432&pgno=2 • http://www.juniper.net/security/auto/vulnerabilities/vuln19998.html •http://www.blackhat.com/presentations/bh-usa-02/bh-us-02-convery- switches.pdf • http://www.askapache.com/security/hacking-vlan-switched-networks.html • http://marc.info/?l=bugtraq&m=116300682804339&w=2 • http://www.secureroot.com/security/advisories/9809702147.html