EC31012-weekReview

Rules of Engagement Teams selected by instructor Host will read the entire questions. Only after, a team may “buzz”

by raise of hand A team must answer the question within 5 seconds after buzzing in

(must have answer at hand) If the answer is incorrect, the team will lose its turn and another

team may buzz in. No score will be deducted. No negative scores. Maximum score is 100. Once reached, that team will stand down

for others to participate. Teams will earn all points scored at the end of game.

When selecting a question, Teams must only select questions of different value, unless there are no others, but may be from different categories.

All team members will participate and will answer questions Only one round - No Daily Doubles, Double Jeopardy or Final

Jeopardy … and no partial credits!

Jeopardy!TCP/IP Model

Ethernet Internet Protocol

ARP Routing / MITM

Privileges / Buffer

Overflow

10 pts 10 pts 10 pts 10 pts 10 pts 10 pts

20 pts 20 pts 20 pts 20 pts 20 pts 20 pts

40 pts 40 pts 40 pts 40 pts 40 pts 40 pts

60 pts 60 pts 60 pts 60 pts 60 pts 60 pts

10 pts 10 pts 10 pts 10 pts 10 pts 10 pts

20 pts 20 pts 20 pts 20 pts 20 pts 20 pts

40 pts 40 pts 40 pts 40 pts 40 pts 40 pts

60 pts 60 pts 60 pts 60 pts 60 pts 60 pts

Which TCP/IP layer is responsible for processes that provide services to HTTP or FTP?

TCP/IP 10 pts

Application Layer

How many bytes are in a physical address?

Ethernet 10 pts

6 Bytes

Example F2 : 45 : 17 : FF : 71 : A2

Which of the following is not a valid IP address?(a) 192.148.2.0

(b) 0.0.0.0

(c) 200.256.32.104

(d) 172.31.22.48

Internet Protocol 10 pts

Maximum octet value = 255

Which two layers does the Address Resolution Protocol (ARP) involve?

ARP 10 pts

Layer 2 (Data Link)&

Layer 3 (Network)

Routing tables are maintained on which of the following:

(a) routers

(b) host computers

(c) both a & b

(d) neither

Routing Tables 10 pts

TRUE/FALSE: It is best to order the routing table by decreasing mask value.

Routing/MITM 10 pts

True! This is “longest mask matching” principle

What does the Linux command sudo do?

Privileges/Buffer Overflow 10 pts

Executes a single command as the root user!

The Transport layer is encapsulated by which layer?

TCP/IP 20 pts

Network Layer (Layer 3)

What is the purpose of the CRC field in an Ethernet frame?

Ethernet 20 pts

Used for Error Detection

What is the network address for the IP address 200.32.33.234 / 23 ?

Internet Protocol 20 pts

200. 32.00100001.11101010

200. 32.00100000.00000000

(Host bits)(Network bits)

Zero out the host bits to get…

200.32.32.0

(mask)

(IP address)

(Network ID)

255.255.11111110.00000000(Mask)

An evil attacker launching an ARP-spoof attempts to associate his ___________ address with the victim’s ___________ address.

Answer choices: hardware or IP

ARP 20 pts

hardwareIP

Routing/MITM 20 pts

If a router receives a packet with a destination IP address that does not match any of the networks on the routing table, what does the router do with it?

The router sends it to the default router.

This is often indicated in the routing table by:Mask NetworkAny Any

or/0 0.0.0.0

Privileges/Buffer Overflow 20 pts

What does setting the setuid permission on an executable program do?

Whenever the program is executed it will behave as though it were being executed by the owner!

TCP/IP 40 pts What is the name of the collection of 1’s and 0’s

at layers 5 through 2?

Layer 5 – “Message”Layer 4 – “Segment”Layer 3 – “Packet or Datagram”Layer 2 – “Frame”

Calculate the bandwidth seen by user 3 if each network is connected via 10 Mbps Ethernet.

Ethernet 40 pts

1

23

4

5

6

B1 B2

10Mbps ÷ 3 = 3.33Mbps

How many addresses can be assigned to hosts on the network 138.43.29.128 / 26 ?

Internet Protocol 40 pts

32 total bits – 26 network bits = 6 host bits

26-2=62 addresses assignable to hosts.

Account for the broadcastand network addresses.

What two types of ARP messages exist?

What is the fundamental problem with ARP that allows an ARP-spoof to be possible?

ARP 40 pts

ARP Request&

ARP Reply

An ARP reply can be sent (and be accepted!) without an ARP request

Routing/MITM 40 pts Fill in the missing information in the routing table for

R1.

Privileges/Buffer Overflow 40 pts

What is the correct order for arranging the payload in a buffer overflow attack, and what are their purposes? Choices are given below:

The exploit (shellcode)

Repeated return addresses

NOP sledNOP Sled – It is a series of “no operation” commands that lets the hacker be a bit off with the return address, so that the return address just has to point anywhere within the NOP sled. Otherwise, the return address would need to be the precise first address of the exploit.

The exploit – This is the executable program.

Repeated return addresses – The return address points towards the exploit as the next instruction (however, see the note regarding the NOP sled). It is repeated so that the hacker would have a number of chances to get the address correctly positioned in the Return Address field in the stack.

Suppose an application entity wants to send a 100 byte message to a peer entity. If each layer from 4-2 appends a 15 byte header, what percentage of the total frame size is actual application entity data?

TCP/IP 60 pts

[100 / (100+15+15+15) ] x100 = 69%

Ethernet 60 pts Assume the Network layer passes the Data Link

layer 6030 bytes of information to transmit. How many Ethernet frames will be required?

6030÷1500 = 4.02 thus 5 Frames

What is the block of addresses assigned to the network 56.45.100.0 / 23 ?

Internet Protocol 60 pts

56.45.01100100.00000000

56.45.01100100.00000000

56.45.01100101.11111111

(Network bits) (Host bits)

= 56.45.100.0 (First Address)

= 56.45.101.255 (Last Address)

(mask)

. .

.

N1 : L1N2 : L2N3 : L3N4 : L4N5 : L5

You are user C in the network below. Design an ARP Spoofing attack on User D. What changes would you make to the ARP cache?

ARP 60 pts

L3

Routing/MITM 60 pts Design an MITM attack to divert traffic from the server

Target’sNetwork

40 .230 .45 .128

00101000 11100110 00101101 1 0 0 0 0 0 0 0

Target’sIP Address

40 .230 .45 .161

00101000 11100110 00101101 1 0 1 0 0 0 0 1

Attacker’sLie

40 .230 .45 .160

00101000 11100110 00101101 1 0 1 0 0 0 0 0

40.230.45.161

Ans: 40.230.45.160 / 27

Other possible Answers: 40.230.45.160 / 2840.230.45.160 / 2940.230.45.160 / 3040.230.45.160 / 31

Target’sNetwork

40 .230 .45 .128

00101000 11100110 00101101 1 0 0 0 0 0 0 0

Target’sIP Address

40 .230 .45 .161

00101000 11100110 00101101

Attacker’sLie

Name and describe two technical solutions to prevent a buffer overflow attack.

Privileges/Buffer Overflow 60 pts

The non-executable stack: The CPU will not execute any machine instructions located in the portion of main memory reserved for the stack.

The stack canary: The CPU checks a known value in memory just prior to the location of the return address (to make sure it was not changed) before resetting the EIP.

Address space layout randomization: The stack and the heap are placed in random memory locations, preventing the hacker from easily predicting return addresses’ location.