ISC sscp practice test

Systems Security Certified Practitioner Exam

Last exam update: May 13 ,2024
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Question 1

Which of the following virus types changes some of its characteristics as it spreads?

  • A. Boot Sector
  • B. Parasitic
  • C. Stealth
  • D. Polymorphic
Answer:

D

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
A Polymorphic virus produces varied but operational copies of itself in hopes of evading anti-virus
software.
The following answers are incorrect:
boot sector. Is incorrect because it is not the best answer. A boot sector virus attacks the boot sector
of a drive. It describes the type of attack of the virus and not the characteristics of its composition.
parasitic. Is incorrect because it is not the best answer. A parasitic virus attaches itself to other files
but does not change its characteristics.
stealth. Is incorrect because it is not the best answer. A stealth virus attempts to hide changes of the
affected files but not itself.

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Question 2

In computing what is the name of a non-self-replicating type of malware program containing
malicious code that appears to have some useful purpose but also contains code that has a malicious
or harmful purpose imbedded in it, when executed, carries out actions that are unknown to the
person installing it, typically causing loss or theft of data, and possible system harm.

  • A. virus
  • B. worm
  • C. Trojan horse.
  • D. trapdoor
Answer:

C

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
A trojan horse is any code that appears to have some useful purpose but also contains code that has
a malicious or harmful purpose imbedded in it. A Trojan often also includes a trapdoor as a means to
gain access to a computer system bypassing security controls.
Wikipedia defines it as:
A Trojan horse, or Trojan, in computing is a non-self-replicating type of malware program containing
malicious code that, when executed, carries out actions determined by the nature of the Trojan,
typically causing loss or theft of data, and possible system harm. The term is derived from the story
of the wooden horse used to trick defenders of Troy into taking concealed warriors into their city in
ancient Greece, because computer Trojans often employ a form of social engineering, presenting
themselves as routine, useful, or interesting in order to persuade victims to install them on their
computers.
The following answers are incorrect:
virus. Is incorrect because a Virus is a malicious program and is does not appear to be harmless, it's
sole purpose is malicious intent often doing damage to a system. A computer virus is a type of
malware that, when executed, replicates by inserting copies of itself (possibly modified) into other
computer programs, data files, or the boot sector of the hard drive; when this replication succeeds,
the affected areas are then said to be "infected".
worm. Is incorrect because a Worm is similiar to a Virus but does not require user intervention to
execute. Rather than doing damage to the system, worms tend to self-propagate and devour the
resources of a system. A computer worm is a standalone malware computer program that replicates
itself in order to spread to other computers. Often, it uses a computer network to spread itself,
relying on security failures on the target computer to access it. Unlike a computer virus, it does not
need to attach itself to an existing program. Worms almost always cause at least some harm to the
network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify
files on a targeted computer.
trapdoor. Is incorrect because a trapdoor is a means to bypass security by hiding an entry point into a
system. Trojan Horses often have a trapdoor imbedded in them.
References:
http://en.wikipedia.org/wiki/Trojan_horse_%28computing%29
and
http://en.wikipedia.org/wiki/Computer_virus
and
http://en.wikipedia.org/wiki/Computer_worm
and
http://en.wikipedia.org/wiki/Backdoor_%28computing%29

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Question 3

Which of the following service is a distributed database that translate host name to IP address to IP
address to host name?

  • A. DNS
  • B. FTP
  • C. SSH
  • D. SMTP
Answer:

A

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services,
or any resource connected to the Internet or a private network. It associates information from
domain names with each of the assigned entities. Most prominently, it translates easily memorized
domain names to the numerical IP addresses needed for locating computer services and devices
worldwide. The Domain Name System is an essential component of the functionality of the Internet.
This article presents a functional description of the Domain Name System.
For your exam you should know below information general Internet terminology:
Network access point - Internet service providers access internet using net access point.A Network
Access Point (NAP) was a public network exchange facility where Internet service providers (ISPs)
connected with one another in peering arrangements. The NAPs were a key component in the
transition from the 1990s NSFNET era (when many networks were government sponsored and
commercial traffic was prohibited) to the commercial Internet providers of today. They were often
points of considerable Internet congestion.
Internet Service Provider (ISP) - An Internet service provider (ISP) is an organization that provides
services for accessing, using, or participating in the Internet. Internet service providers may be
organized in various forms, such as commercial, community-owned, non-profit, or otherwise
privately owned. Internet services typically provided by ISPs include Internet access, Internet transit,
domain name registration, web hosting, co-location.
Telnet or Remote Terminal Control Protocol -A terminal emulation program for TCP/IP networks
such as the Internet. The Telnet program runs on your computer and connects your PC to a server on
the network. You can then enter commands through the Telnet program and they will be executed as
if you were entering them directly on the server console. This enables you to control the server and
communicate with other servers on the network. To start a Telnet session, you must log in to a server
by entering a valid username and password. Telnet is a common way to remotely control Web
servers.
Internet Link- Internet link is a connection between Internet users and the Internet service
provider.
Secure Shell or Secure Socket Shell (SSH) - Secure Shell (SSH), sometimes known as Secure Socket
Shell, is a UNIX-based command interface and protocol for securely getting access to a remote
computer. It is widely used by network administrators to control Web and other kinds of servers
remotely. SSH is actually a suite of three utilities - slogin, ssh, and scp - that are secure versions of the
earlier UNIX utilities, rlogin, rsh, and rcp. SSH commands are encrypted and secure in several ways.
Both ends of the client/server connection are authenticated using a digital certificate, and passwords
are protected by being encrypted.
Domain Name System (DNS) - The Domain Name System (DNS) is a hierarchical distributed naming
system for computers, services, or any resource connected to the Internet or a private network. It
associates information from domain names with each of the assigned entities. Most prominently, it
translates easily memorized domain names to the numerical IP addresses needed for locating
computer services and devices worldwide. The Domain Name System is an essential component of
the functionality of the Internet. This article presents a functional description of the Domain Name
System.
File Transfer Protocol (FTP) - The File Transfer Protocol or FTP is a client/server application that is
used to move files from one system to another. The client connects to the FTP server, authenticates
and is given access that the server is configured to permit. FTP servers can also be configured to
allow anonymous access by logging in with an email address but no password. Once connected, the
client may move around between directories with commands available
Simple Mail Transport Protocol (SMTP) - SMTP (Simple Mail Transfer Protocol) is a TCP/IP protocol
used in sending and receiving e-mail. However, since it is limited in its ability to queue messages at
the receiving end, it is usually used with one of two other protocols, POP3 or IMAP, that let the user
save messages in a server mailbox and download them periodically from the server. In other words,
users typically use a program that uses SMTP for sending e-mail and either POP3 or IMAP for
receiving e-mail. On Unix-based systems, send mail is the most widely-used SMTP server for e-mail.
A commercial package, Send mail, includes a POP3 server. Microsoft Exchange includes an SMTP
server and can also be set up to include POP3 support.
The following answers are incorrect:
SMTP - Simple Mail Transport Protocol (SMTP) - SMTP (Simple Mail Transfer Protocol) is a TCP/IP
protocol used in sending and receiving e-mail. However, since it is limited in its ability to queue
messages at the receiving end, it is usually used with one of two other protocols, POP3 or IMAP, that
let the user save messages in a server mailbox and download them periodically from the server. In
other words, users typically use a program that uses SMTP for sending e-mail and either POP3 or
IMAP for receiving e-mail. On Unix-based systems, send mail is the most widely-used SMTP server
for e-mail. A commercial package, Send mail, includes a POP3 server. Microsoft Exchange includes an
SMTP server and can also be set up to include POP3 support.
FTP - The File Transfer Protocol or FTP is a client/server application that is used to move files from
one system to another. The client connects to the FTP server, authenticates and is given access that
the server is configured to permit. FTP servers can also be configured to allow anonymous access by
logging in with an email address but no password. Once connected, the client may move around
between directories with commands available
SSH - Secure Shell (SSH), sometimes known as Secure Socket Shell, is a UNIX-based command
interface and protocol for securely getting access to a remote computer. It is widely used by network
administrators to control Web and other kinds of servers remotely. SSH is actually a suite of three
utilities - slogin, ssh, and scp - that are secure versions of the earlier UNIX utilities, rlogin, rsh, and
rcp. SSH commands are encrypted and secure in several ways. Both ends of the client/server
connection are authenticated using a digital certificate, and passwords are protected by being
encrypted.
The following reference(s) were/was used to create this question;
CISA review
manual 2014 page number 273 and 274

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Question 4

While using IPsec, the ESP and AH protocols both provides integrity services. However when using
AH, some special attention needs to be paid if one of the peers uses NAT for address translation
service. Which of the items below would affects the use of AH and its Integrity Check Value (ICV)
the most?

  • A. Key session exchange
  • B. Packet Header Source or Destination address
  • C. VPN cryptographic key size
  • D. Crypotographic algorithm used
Answer:

B

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
It may seem odd to have two different protocols that provide overlapping functionality.
AH provides authentication and integrity, and ESP can provide those two functions and
confidentiality.
Why even bother with AH then?
In most cases, the reason has to do with whether the environment is using network address
translation (NAT). IPSec will generate an integrity check value (ICV), which is really the same thing as
a MAC value, over a portion of the packet. Remember that the sender and receiver generate their
own values. In IPSec, it is called an ICV value. The receiver compares her ICV value with the one sent
by the sender. If the values match, the receiver can be assured the packet has not been modified
during transmission. If the values are different, the packet has been altered and the receiver discards
the packet.
The AH protocol calculates this ICV over the data payload, transport, and network headers. If the
packet then goes through a NAT device, the NAT device changes the IP address of the packet. That is
its job. This means a portion of the data (network header) that was included to calculate the ICV
value has now changed, and the receiver will generate an ICV value that is different from the one
sent with the packet, which means the packet will be discarded automatically.
The ESP protocol follows similar steps, except it does not include the network header portion when
calculating its ICV value. When the NAT device changes the IP address, it will not affect the receivers
ICV value because it does not include the network header when calculating the ICV.
Here is a tutorial on IPSEC from the Shon Harris Blog:
The Internet Protocol Security (IPSec) protocol suite provides a method of setting up a secure
channel for protected data exchange between two devices. The devices that share this secure
channel can be two servers, two routers, a workstation and a server, or two gateways between
different networks. IPSec is a widely accepted standard for providing network layer protection. It can
be more flexible and less expensive than end-to end and link encryption methods.
IPSec has strong encryption and authentication methods, and although it can be used to enable
tunneled communication between two computers, it is usually employed to establish virtual private
networks (VPNs) among networks across the Internet.
IPSec is not a strict protocol that dictates the type of algorithm, keys, and authentication method to
use. Rather, it is an open, modular framework that provides a lot of flexibility for companies when
they choose to use this type of technology. IPSec uses two basic security protocols: Authentication
Header (AH) and Encapsulating Security Payload (ESP). AH is the authenticating protocol, and ESP is
an authenticating and encrypting protocol that uses cryptographic mechanisms to provide source
authentication, confidentiality, and message integrity.
IPSec can work in one of two modes: transport mode, in which the payload of the message is
protected, and tunnel mode, in which the payload and the routing and header information are
protected. ESP in transport mode encrypts the actual message information so it cannot be sniffed
and uncovered by an unauthorized entity. Tunnel mode provides a higher level of protection by also
protecting the header and trailer data an attacker may find useful. Figure 8-26 shows the high-level
view of the steps of setting up an IPSec connection.
Each device will have at least one security association (SA) for each VPN it uses. The SA, which is
critical to the IPSec architecture, is a record of the configurations the device needs to support an
IPSec connection. When two devices complete their handshaking process, which means they have
agreed upon a long list of parameters they will use to communicate, these data must be recorded
and stored somewhere, which is in the SA.
The SA can contain the authentication and encryption keys, the agreed-upon algorithms, the key
lifetime, and the source IP address. When a device receives a packet via the IPSec protocol, it is the
SA that tells the device what to do with the packet. So if device B receives a packet from device C via
IPSec, device B will look to the corresponding SA to tell it how to decrypt the packet, how to properly
authenticate the source of the packet, which key to use, and how to reply to the message if
necessary.
SAs are directional, so a device will have one SA for outbound traffic and a different SA for inbound
traffic for each individual communication channel. If a device is connecting to three devices, it will
have at least six SAs, one for each inbound and outbound connection per remote device. So how can
a device keep all of these SAs organized and ensure that the right SA is invoked for the right
connection? With the mighty secu rity parameter index (SPI), thats how. Each device has an SPI that
keeps track of the different SAs and tells the device which one is appropriate to invoke for the
different packets it receives. The SPI value is in the header of an IPSec packet, and the device reads
this value to tell it which SA to consult.
IPSec can authenticate the sending devices of the packet by using MAC (covered in the earlier
section, The One-Way Hash). The ESP protocol can provide authentication, integrity, and
confidentiality if the devices are configured for this type of functionality.
So if a company just needs to make sure it knows the source of the sender and must be assured of
the integrity of the packets, it would choose to use AH. If the company would like to use these
services and also have confidentiality, it would use the ESP protocol because it provides encryption
functionality. In most cases, the reason ESP is employed is because the company must set up a
secure VPN connection.
It may seem odd to have two different protocols that provide overlapping functionality. AH provides
authentication and integrity, and ESP can provide those two functions and confidentiality. Why even
bother with AH then? In most cases, the reason has to do with whether the environment is using
network address translation (NAT). IPSec will generate an integrity check value (ICV), which is really
the same thing as a MAC value, over a portion of the packet. Remember that the sender and receiver
generate their own values. In IPSec, it is called an ICV value. The receiver compares her ICV value
with the one sent by the sender. If the values match, the receiver can be assured the packet has not
been modified during transmission. If the values are different, the packet has been altered and the
receiver discards the packet.
The AH protocol calculates this ICV over the data payload, transport, and network headers. If the
packet then goes through a NAT device, the NAT device changes the IP address of the packet. That is
its job. This means a portion of the data (network header) that was included to calculate the ICV
value has now changed, and the receiver will generate an ICV value that is different from the one
sent with the packet, which means the packet will be discarded automatically.
The ESP protocol follows similar steps, except it does not include the network header portion when
calculating its ICV value. When the NAT device changes the IP address, it will not affect the receivers
ICV value because it does not include the network header when calculating the ICV.
Because IPSec is a framework, it does not dictate which hashing and encryption algorithms are to be
used or how keys are to be exchanged between devices. Key management can be handled manually
or automated by a key management protocol. The de facto standard for IPSec is to use Internet Key
Exchange (IKE), which is a combination of the ISAKMP and OAKLEY protocols. The Internet Security
Association and Key Management Protocol (ISAKMP) is a key exchange architecture that is
independent of the type of keying mechanisms used. Basically, ISAKMP provides the framework of
what can be negotiated to set up an IPSec connection (algorithms, protocols, modes, keys). The
OAKLEY protocol is the one that carries out the negotiation process. You can think of ISAKMP as
providing the playing field (the infrastructure) and OAKLEY as the guy running up and down the
playing field (carrying out the steps of the negotiation).
IPSec is very complex with all of its components and possible configurations. This complexity is what
provides for a great degree of flexibility, because a company has many different configuration choices
to achieve just the right level of protection. If this is all new to you and still confusing, please review
one or more of the following references to help fill in the gray areas.
The following answers are incorrect:
The other options are distractors.
The following reference(s) were/was used to create this question;
Shon Harris
, CISSP All-in-One Exam Guide- fiveth edition, page 759
and
https://neodean.wordpress.com/tag/security-protocol/

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Question 5

At which layer of ISO/OSI does the fiber optics work?

  • A. Network layer
  • B. Transport layer
  • C. Data link layer
  • D. Physical layer
Answer:

D

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
The Answer: Physical layer The Physical layer is responsible for the transmission of the data
Explanation:through the physical medium. This includes such things as cables. Fiber optics is a
cabling mechanism which works at Physical layer of OSI model
All of the other answers are incorrect.
The following reference(s) were/was used to create this question;
Shon Harris
all in one - Chapter 7 (Cabling)

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Question 6

Which of the following media is MOST resistant to EMI interference?

  • A. microwave
  • B. fiber optic
  • C. twisted pair
  • D. coaxial cable
Answer:

B

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
A fiber optic cable is a physical medium that is capable of conducting modulated light trasmission.
Fiber optic cable carries signals as light waves, thus creating higher trasmission speeds and greater
distances due to less attenuation. This type of cabling is more difficult to tap than other cabling and is
most resistant to interference, especially EMI.
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 103).

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Question 7

What is a packet sniffer?

  • A. It tracks network connections to off-site locations.
  • B. It monitors network traffic for illegal packets.
  • C. It scans network segments for cabling faults.
  • D. It captures network traffic for later analysis.
Answer:

D

User Votes:
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C
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Explanation:
Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

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Question 8

Which one of the following is used to provide authentication and confidentiality for e-mail
messages?

  • A. Digital signature
  • B. PGP
  • C. IPSEC AH
  • D. MD4
Answer:

B

User Votes:
A
50%
B
50%
C
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D
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Explanation:
Instead of using a Certificate Authority, PGP uses a "Web of Trust", where users can certify each other
in a mesh model, which is best applied to smaller groups.
In cryptography, a web of trust is a concept used in PGP, GnuPG, and other OpenPGP compatible
systems to establish the authenticity of the binding between a public key and its owner. Its
decentralized trust model is an alternative to the centralized trust model of a public key
infrastructure (PKI), which relies exclusively on a certificate authority (or a hierarchy of such). The
web of trust concept was first put forth by PGP creator Phil Zimmermann in 1992 in the manual for
PGP version 2.0.
Pretty Good Privacy (PGP) is a data encryption and decryption computer program that provides
cryptographic privacy and authentication for data communication. PGP is often used for signing,
encrypting and decrypting texts, E-mails, files, directories and whole disk partitions to increase the
security of e-mail communications. It was created by Phil Zimmermann in 1991.
As per Shon Harris's book:
Pretty Good Privacy (PGP) was designed by Phil Zimmerman as a freeware e-mail security program
and was released in 1991. It was the first widespread public key encryption program. PGP is a
complete cryptosystem that uses cryptographic protection to protect e-mail and files. It can use RSA
public key encryption for key management and use IDEA symmetric cipher for bulk encryption of
data, although the user has the option of picking different types of algorithms for these functions.
PGP can provide confidentiality by using the IDEA encryption algorithm, integrity by using the MD5
hashing algorithm, authentication by using the public key certificates, and nonrepudiation by using
cryptographically signed messages. PGP initially used its own type of digital certificates rather than
what is used in PKI, but they both have similar purposes. Today PGP support X.509 V3 digital
certificates.
Reference(s) used for this question;
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 169).
Shon Harris, CISSP All in One book
https://en.wikipedia.org/wiki/Pretty_Good_Privacy
TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

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Question 9

Why is traffic across a packet switched network difficult to monitor?

  • A. Packets are link encrypted by the carrier
  • B. Government regulations forbids monitoring
  • C. Packets can take multiple paths when transmitted
  • D. The network factor is too high
Answer:

C

User Votes:
A
50%
B
50%
C
50%
D
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Explanation:
With a packet switched network, packets are difficult to monitor because they can be transmitted
using different paths.
A packet-switched network is a digital communications network that groups all transmitted data,
irrespective of content, type, or structure into suitably sized blocks, called packets. The network over
which packets are transmitted is a shared network which routes each packet independently from all
others and allocates transmission resources as needed.
The principal goals of packet switching are to optimize utilization of available link capacity, minimize
response times and increase the robustness of communication. When traversing network adapters,
switches and other network nodes, packets are buffered and queued, resulting in variable delay and
throughput, depending on the traffic load in the network.
Most modern Wide Area Network (WAN) protocols, including TCP/IP, X.25, and Frame Relay, are
based on packet-switching technologies. In contrast, normal telephone service is based on a circuit-
switching technology, in which a dedicated line is allocated for transmission between two parties.
Circuit-switching is ideal when data must be transmitted quickly and must arrive in the same order in
which it's sent. This is the case with most real-time data, such as live audio and video. Packet
switching is more efficient and robust for data that can withstand some delays in transmission, such
as e-mail messages and Web pages.
All of the other answer are wrong
Reference(s) used for this question;
TIPTON,
Hal, (ISC)2, Introduction to the CISSP Exam presentation.
and
https://en.wikipedia.org/wiki/Packet-switched_network
and
http://www.webopedia.com/TERM/P/packet_switching.html

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Question 10

Another name for a VPN is a:

  • A. tunnel
  • B. one-time password
  • C. pipeline
  • D. bypass
Answer:

A

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

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Question 11

Layer 4 of the OSI stack is known as:

  • A. the data link layer
  • B. the transport layer
  • C. the network layer
  • D. the presentation layer
Answer:

B

User Votes:
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B
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Explanation:
Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

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Question 12

Why does fiber optic communication technology have significant security advantage over other
transmission technology?

  • A. Higher data rates can be transmitted.
  • B. Interception of data traffic is more difficult.
  • C. Traffic analysis is prevented by multiplexing.
  • D. Single and double-bit errors are correctable.
Answer:

B

User Votes:
A
50%
B
50%
C
50%
D
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Explanation:
It would be correct to select the first answer if the world "security" was not in the question.
Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

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Question 13

Which of the following packets should NOT be dropped at a firewall protecting an organization's
internal network?

  • A. Inbound packets with Source Routing option set
  • B. Router information exchange protocols
  • C. Inbound packets with an internal address as the source IP address
  • D. Outbound packets with an external destination IP address
Answer:

D

User Votes:
A
50%
B
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C
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D
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Explanation:
Normal outbound traffic has an internal source IP address and an external destination IP address.
Traffic with an internal source IP address should only come from an internal interface. Such packets
coming from an external interface should be dropped.
Packets with the source-routing option enabled usually indicates a network intrusion attempt.
Router information exchange protocols like RIP and OSPF should be dropped to avoid having internal
routing equipment being reconfigured by external agents.
Source: STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 10: The
Perfect Firewall.

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Question 14

In the context of network enumeration by an outside attacker and possible Distributed Denial of
Service (DDoS) attacks, which of the following firewall rules is not appropriate to protect an
organization's internal network?

  • A. Allow echo reply outbound
  • B. Allow echo request outbound
  • C. Drop echo request inbound
  • D. Allow echo reply inbound
Answer:

A

User Votes:
A
50%
B
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C
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D
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Explanation:
Echo replies outbound should be dropped, not allowed. There is no reason for any internet users to
send ICMP ECHO Request to your interal hosts from the internet. If they wish to find out if a service
is available, they can use a browser to connect to your web server or simply send an email if they
wish to test your mail service.
Echo replies outbound could be used as part of the SMURF amplification attack where someone will
send ICMP echo requests to gateways broadcast addresses in order to amplify the request by X
number of users sitting behind the gateway.
By allowing inbound echo requests and outbound echo replies, it makes it easier for attackers to
learn about the internal network as well by performing a simply ping sweep. ICMP can also be used
to find out which host has been up and running the longest which would indicates which patches are
missing on the host if a critical patch required a reboot.
ICMP can also be use for DDoS attacks, so you should strictly limit what type of ICMP traffic would be
allowed to flow through your firewall.
On top of all this, tools such as LOKI could be use as a client-server application to transfer files back
and forward between the internat and some of your internal hosts. LOKI is a client/server program
published in the online publication Phrack . This program is a working proof-of-concept to
demonstrate that data can be transmitted somewhat secretly across a network by hiding it in traffic
that normally does not contain payloads. The example code can tunnel the equivalent of a Unix
RCMD/RSH session in either ICMP echo request (ping) packets or UDP traffic to the DNS port. This is
used as a back door into a Unix system after root access has been compromised. Presence of LOKI on
a system is evidence that the system has been compromised in the past.
The outbound echo request and inbound echo reply allow internal users to verify connectivity with
external hosts.
The following answers are incorrect:
Allow echo request outbound The outbound echo request and inbound echo reply allow internal
users to verify connectivity with external hosts.
Drop echo request inbound There is no need for anyone on the internet to attempt pinging your
internal hosts.
Allow echo reply inbound The outbound echo request and inbound echo reply allow internal users
to verify connectivity with external hosts.
Reference(s) used for this question;
http://www.phrack.org/issues.html?issue=49&id=6
STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 10: The Perfect
Firewall.

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Question 15

Which of the following is the primary security feature of a proxy server?

  • A. Virus Detection
  • B. URL blocking
  • C. Route blocking
  • D. Content filtering
Answer:

D

User Votes:
A
50%
B
50%
C
50%
D
50%

Explanation:
In many organizations, the HTTP proxy is used as a means to implement content filtering, for
instance, by logging or blocking traffic that has been defined as, or is assumed to be nonbusiness
related for some reason.
Although filtering on a proxy server or firewall as part of a layered defense can be quite effective to
prevent, for instance, virus infections (though it should never be the only protection against viruses),
it will be only moderately effective in preventing access to unauthorized services (such as certain
remote-access services or file sharing), as well as preventing the download of unwanted content.
HTTP Tunneling.
HTTP tunneling is technically a misuse of the protocol on the part of the designer of such tunneling
applications. It has become a popular feature with the rise of the first streaming video and audio
applications and has been implemented into many applications that have a market need to bypass
user policy restrictions.
Usually, HTTP tunneling is applied by encapsulating outgoing traffic from an application in an HTTP
request and incoming traffic in a response. This is usually not done to circumvent security, but rather,
to be compatible with existing firewall rules and allow an application to function through a firewall
without the need to apply special rules, or additional configurations.
The following are incorrect choices:
Virus Detection A proxy is not best at detection malware and viruses within content. A antivirus
product would be use for that purpose.
URL blocking This would be a subset of Proxying, based on the content some URL's may be blocked
by the proxy but it is not doing filtering based on URL addresses only. This is not the BEST answer.
Route blocking This is a function that would be done by Intrusion Detection and Intrusion prevention
system and not the proxy. This could be done by filtering devices such as Firewalls and Routers as
well. Again, not the best choice.
Reference(s) used for this
Question;
Hernandez
CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle
Locations 6195-6201). Auerbach Publications. Kindle Edition.

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