ISC SSCP Exam Made Easy: Step-by-Step Preparation Guide

An IP spoofing attack is used to convince a system that it is communication with a known entity that gives an intruder access. It involves modifying the source address of a packet for a trusted source's address. A TCP sequence number attack involves hijacking a session between a host and a target by predicting the target's choice of an initial TCP sequence number. Piggybacking refers to an attacker gaining unauthorized access to a system by using a legitimate user's connection. A teardrop attack consists of modifying the length and fragmentation offset fields in sequential IP packets so the target system becomes confused and crashes after it receives contradictory instructions on how the fragments are offset on these packets.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 77).

Packet filtering firewalls use routers with packet filtering rules to grant or deny access based on source address, destination address, and port.

They offer minimum security but at a very low cost, and can be an appropriate choice for a low-risk environment.

Source: TIPTON, Harold F. & KRAUSE, Micki, Information Security Management Handbook, 4th edition (volume 1), 2000, CRC Press, Chapter 3, Secured Connections to External Networks (page 60).

Firewalls can protect a network at multiple layers of the OSI models, however most of the firewalls do not have the ability to monitor the payload of the packets and see if an application level attack is taking place.

Today there are a new breed of firewall called Unified Threat Managers or UTM. They are a collection of products on a single computer and not necessarily a typical firewall. A UTM can address all of the layers but typically a firewall cannot.

Firewalls are security checkpoints at the boundaries of internal networks through which every packet must pass and be inspected, hence they create bottlenecks between the internal and external networks. But since external connections are relatively slow compared to modern computers, the latency caused by this bottleneck can almost be transparent.

By implementing the concept of border security, they centralize security services in machines optimized and dedicated to the task, thus relieving the other hosts on the network from that function.

Source: STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 1: Understanding Firewalls.

IP spoofing is used to convince a system that it is communicating with a known entity that gives an intruder access. IP spoofing attacks is a common session hijacking attack.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 77).

The data link layer (layer 2) establishes the communications link between individual devices over a physical link or channel. It also ensures that messages are delivered to the proper device and translates the messages from layers above into bits for the physical layer (layer 1) to transmit.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 83).

Once the merchant server has been authenticated by the browser client, the browser generates a master secret that is to be shared only between the server and client. This secret serves as a seed to generate the session (private) keys. The master secret is then encrypted with the merchant's public key and sent to the server. The fact that the master secret is generated by the client's browser provides the client assurance that the server is not reusing keys that would have been used in a previous session with another client.

Source: ANDRESS, Mandy, Exam Cram CISSP, Coriolis, 2001, Chapter 6: Cryptography (page 112).

Also: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2001, page 569.

The Answer: Application. The Layer 7 Application Layer of the Open Systems Interconnect (OSI) Reference Model is a service for applications and Operating Systems data transmission, for example FTP, TFTP, SNMP, and SMTP.

The following answers are incorrect:

Network. The Network layer moves information between hosts that are not physically connected. It deals with routing of information. IP is a protocol that is used in Network Layer. FTP, TFTP, SNMP, and SMTP do not reside at the Layer 3 Network Layer in the OSI Reference Model.

Presentation. The Presentation Layer is concerned with the formatting of data into a standard presentation such as

ASCII. FTP, TFTP, SNMP, and SMTP do not reside at the Layer 6 Presentation Layer in the OSI Reference Model.

Transport. The Transport Layer creates an end-to-end transportation between peer hosts. The transmission can be connectionless and unreliable such as UDP, or connection-oriented and ensure error-free delivery such as TCP. FTP, TFTP, SNMP, and SMTP do not reside at the Layer 4 Transportation Layer in the OSI Reference Model.

The following reference(s) were/was used to create this question: Reference: OSI/ISO.

Shon Harris AIO v.3 p. 420-421

ISC2 OIG, 2997 p.412-413

Only fiber optic cables are not affected by crosstalk or interference.

For your exam you should know the information about transmission media:

Copper Cable

Copper cable is very simple to install and easy to tap. It is used mostly for short distance and supports voice and data.

Copper has been used in electric wiring since the invention of the electromagnet and the telegraph in the 1820s.The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor.

Copper is the electrical conductor in many categories of electrical wiring. Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Copper and its alloys are also used to make electrical contacts. Electrical wiring in buildings is the most important market for the copper industry. Roughly half of all copper mined is used to manufacture electrical wire and cable conductors.

Copper Cable

Image Source - http://i00.i.aliimg.com/photo/v0/570456138/FRLS_HR_PVC_Copper_Cable.jpg

Coaxial cable

Coaxial cable, or coax (pronounced 'ko.aks), is a type of cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables also have an insulating outer sheath or jacket. The term coaxial comes from the inner conductor and the outer shield sharing a geometric axis. Coaxial cable was invented by English engineer and mathematician Oliver Heaviside, who patented the design in 1880.Coaxial cable differs from other shielded cable used for carrying lower-frequency signals, such as audio signals, in that the dimensions of the cable are controlled to give a precise, constant conductor spacing, which is needed for it to function efficiently as a radio frequency transmission line.

Coaxial cable are expensive and does not support many LAN's. It supports data and video

Coaxial Cable

Image Source - http://www.tlc-direct.co.uk/Images/Products/size_3/CARG59.JPG

Fiber optics

An optical fiber cable is a cable containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. Different types of cable are used for different applications, for example long distance telecommunication, or providing a high-speed data connection between different parts of a building.

Fiber optics used for long distance, hard to splice, not vulnerable to cross talk and difficult to tap. It supports voice data, image and video.

Radio System

Radio systems are used for short distance,cheap and easy to tap.

Radio is the radiation (wireless transmission) of electromagnetic signals through the atmosphere or free space.

Information, such as sound, is carried by systematically changing (modulating) some property of the radiated waves, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.

Fiber Optics

Image Source - http://aboveinfranet.com/wp-content/uploads/2014/04/fiber-optic-cables-above-infranet-solutions.jpg

Microwave radio system

Microwave transmission refers to the technology of transmitting information or energy by the use of radio waves whose wavelengths are conveniently measured in small numbers of centimetre; these are called microwaves.

Microwaves are widely used for point-to-point communications because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it. A disadvantage is that microwaves are limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio waves can.

Microwave radio transmission is commonly used in point-to-point communication systems on the surface of the Earth, in satellite communications, and in deep space radio communications. Other parts of the microwave radio band are used for radars, radio navigation systems, sensor systems, and radio astronomy.

Microwave radio systems are carriers for voice data signal, cheap and easy to tap.

Microwave Radio System

Image Source - http://www.valiantcom.com/images/applications/e1_digital_microwave_radio.gif

Satellite Radio Link

Satellite radio is a radio service broadcast from satellites primarily to cars, with the signal broadcast nationwide, across a much wider geographical area than terrestrial radio stations. It is available by subscription, mostly commercial free, and offers subscribers more stations and a wider variety of programming options than terrestrial radio.

Satellite radio link uses transponder to send information and easy to tap.

The following answers are incorrect:

Copper Cable - Copper cable is very simple to install and easy to tap. It is used mostly for short distance and supports voice and data.

Radio System - Radio systems are used for short distance,cheap and easy to tap.

Satellite Radio Link - Satellite radio link uses transponder to send information and easy to tap.

The following reference(s) were/was used to create this question:

CISA review manual 2014 page number 265 &

Official ISC2 guide to CISSP CBK 3rd Edition Page number 233

TACACS+ is a proprietary Cisco enhancement to TACACS and is more robust than RADIUS. PAP is not a remote access authentication system but a remote node security protocol.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 122).

Infrared is generally considered to be more secure to eavesdropping than multidirectional radio transmissions because infrared requires direct line-of-sight paths.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 173).

L2TP and PPTP were both designed for individual client to server connections; they enable only a single point-to-point connection per session. Dial-up VPNs use L2TP often. Both L2TP and PPTP operate at the data link layer (layer 2) of the OSI model. PPTP uses native PPP authentication and encryption services and L2TP is a combination of PPTP and Layer 2 Forwarding protocol (L2F).

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 95).

The Land attack involves the perpetrator sending spoofed packet(s) with the SYN flag set to the victim's machine on any open port that is listening. The packet(s) contain the same destination and source IP address as the host, causing the victim's machine to reply to itself repeatedly. In addition, most systems experience a total freeze up, where as CTRL-ALT-DELETE fails to work, the mouse and keyboard become non operational and the only method of correction is to reboot via a reset button on the system or by turning the machine off.

The Boink attack, a modified version of the original Teardrop and Bonk exploit programs, is very similar to the Bonk attack, in that it involves the perpetrator sending corrupt UDP packets to the host. It however allows the attacker to attack multiple ports where Bonk was mainly directed to port 53 (DNS).

The Teardrop attack involves the perpetrator sending overlapping packets to the victim, when their machine attempts to re-construct the packets the victim's machine hangs.

A Smurf attack is a network-level attack against hosts where a perpetrator sends a large amount of ICMP echo (ping) traffic at broadcast addresses, all of it having a spoofed source address of a victim. If the routing device delivering traffic to those broadcast addresses performs the IP broadcast to layer 2 broadcast function, most hosts on that IP network will take the ICMP echo request and reply to it with an echo reply each, multiplying the traffic by the number of hosts responding. On a multi-access broadcast network, there could potentially be hundreds of machines to reply to each packet.

Resources:

http://en.wikipedia.org/wiki/Denial-of-service_attack

http://en.wikipedia.org/wiki/LAND

The Application Layer determines the identity of the communication partners and this is where Non-Repudiation service would be provided as well. See the layers below:

DOD Model DoD Model

The following answers are incorrect:

network layer. Is incorrect because the Network Layer mostly has routing protocols, ICMP, IP, and IPSEC. It it not a layer in the DoD Model. It is called the Internet Layer within the DoD model.

transport layer. Is incorrect because the Transport layer provides transparent transfer of data between end users. This is called Host-to-Host on the DoD model but sometimes some books will call it Transport as well on the DoD model.

data link layer. Is incorrect because the Data Link Layer defines the protocols that computers must follow to access the network for transmitting and receiving messages. It is part of the OSI Model. This does not exist on the DoD model, it is called the Link Layer on the DoD model.

The dynamic packet filtering firewall is able to create ACL's on the fly to allow replies on dynamic ports (higher than 1023).

Packet filtering is incorrect. The packet filtering firewall usually requires that the dynamic ports be left open as a group in order to handle this situiation.

Circuit level proxy is incorrect. The circuit level proxy builds a conduit between the trusted and untrusted hosts and does not work by dynamically creating ACL's.

Application level proxy is incorrect. The application level proxy "proxies" for the trusted host in its communications with the untrusted host. It does not dynamically create ACL's to control traffic.

Switches primarily operate at the data link layer (layer 2), although intelligent, extremely fast Layer 3 switching techniques are being more frequently used.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 111).

A Trivial File Transfer Protocol (TFTP) server can be used when configuring network devices to transfer configurations to and from network devices. Many networking devices now support TFTP.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 73).

This is a valid Class C reserved address. For Class C, the reserved addresses are 192.168.0.0 - 192.168.255.255.

The private IP address ranges are defined within RFC 1918:

RFC 1918 private ip address range

The following answers are incorrect:

192.166.42.5 Is incorrect because it is not a Class C reserved address.

192.175.42.5 Is incorrect because it is not a Class C reserved address.

192.1.42.5 Is incorrect because it is not a Class C reserved address.

Containing the dial-up problem is conceptually easy: by installing the Remote Access Server outside the firewall and forcing legitimate users to authenticate to the firewall, any access to internal resources through the RAS can be filtered as would any other connection coming from the Internet.

The use of a TACACS+ Server by itself cannot eliminate hacking.

Setting a modem ring count to 5 may help in defeating war-dialing hackers who look for modem by dialing long series of numbers.

Attaching modems only to non-networked hosts is not practical and would not prevent these hosts from being hacked.

Source: STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 2: Hackers.

Some sites choose not to implement Trivial File Transfer Protocol (TFTP) due to the inherent security risks. TFTP is a UDP-based file transfer program that provides no security. There is no user authentication.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 88.

If the protocol field has a value of 1 then it would indicate it was ICMP.

The following answers are incorrect:

TCP. Is incorrect because the value for a TCP protocol would be 6.

UDP. Is incorrect because the value for an UDP protocol would be 17.

IGMP. Is incorrect because the value for an IGMP protocol would be 2.