Wednesday, October 28, 2009

Lab 6 : Security in Network

1. Discuss the potential perpetrators that can threaten Network security and it goal for attacking network services.

In general network security can been said as a prevention from nosy people from getting data they are not authorized or worse yet, modify messages intended for other recipients. It is concerned with people trying to access remote services that are not authorized to use. Most problems are intentionally caused by malicious people trying to gain some benefit or bring harm to someone else.

2. Network security problems can be divided roughly into FOUR (4) intertwined areas, List and explain in details each area.

Secrecy - also called confidentiality, has to do with keeping information out of the hands of unauthorized users. It protects against disclosure of information to entities not authorized to have that information. Entities might be people or organization.

Authentication - deals with determining whom you are talking to before revealing sensitive information or entering into a business deal.

Non-Repudiation - deals with signatures. It protects user against the threat that the value or existence of the data might be changed in a way inconsistent with the recognized security policy.

Integrity control how - can you be sure that a message you received was really the one sent and not something that a malicious adversary modified in transit.

3. What is the significance difference between the wireshark output in Task 1 and Task 2; explain in detail the function of IPSec in Task 2?

During Task 1, wireshark successful captured both username and password in File Transfer Protocol (FTP). Username = ‘administrator’ and Password = ‘abc123’. But all these things not happen in Task 2, this is because both username and password are already encrypted even the data are captured. This is because in the Task 2, we using IPSec to secure FTP Transaction. IPSec is one of the solutions to safeguard the transmission of data over FTP from being seen by an unauthorized user. It will protect the information from being manipulated.


4. What is the benefit of using IPSec?

IPSec is typically used to attain confidentiality, integrity, and authentication in the transport of data across insecure channels. Though it's original purpose was to secure traffic across public networks, it's implementations are often used to increase the security of private networks as well, since organizations cannot always be sure if weaknesses in their own private networks are susceptible to exploitation. If implemented properly, IPSec provides a private channel for sending and exchanging vulnerable data whether the data is email, ftp traffic, news feeds, partner and supply chain data, medical records, or any other type of TCP/IP based data.

5. Explain what are AH and ESP in IPSec protocol suite?

Authentication Header (AH): ties data in each packet to a verifiable signature (similar to PGP email signatures) that allows you to verify both the identity of the person sending the data and that the data has not been altered. · Encapsulation Payload (ESP): scrambles the data (and even certain sensitive IP addresses) in each packet using hard core encryption. So a sniffer somewhere on the network doesn’t get anything usable.


6. Explain in detail how to enable IPSec option in a linux environment.

Enable-dpd: enables dead peer detection (DPD). DPD is a method for detecting wether any of the hosts for which security associations are set up is unreachable. When this is the case the security associations to that host can be removed. enable-natt: enables NAT traversal (NAT-T). Since NAT alters the IP headers, this causes problems for guaranteeing authenticity of a packet. NAT-T is a method that helps overcoming this problem.

7. Are there any other methods to secure FTP connection other than using IPSec? (list at least 3 methods).

i. SQL Server Integration Services)
ii. SFTP (secure FTP with SSH2 protocol)
iii. FTPS (FTP over SSL) site


Lecture 6 : Security in Networks & Applications

:: Who cause security problem ?

- Hacker, spy, student, businesman, ex - employee, stockrbroker, terrorist, programmer.

:: Network security area :

- authentication, secrecy, non-repudiation, integrity control.

:: Network security issues:

- Sharing, complexity, unknown parameter, many point of attack, unknown path, label format differences, anonymity

:: Threat in Networks

- Privacy, data integrity,authenticity,covert channels, impersonating,eavesdropping,denial of service, packet replay and packet modification.

::Network Security Control

- Encryption, firewall, VPN (Virtual Private Network), SSH Encryption, SSL Encryption , IPSec, kerberos.

Lab 5 : Web Application Security

1.Discuss the differences between GET and POST method in submitting variable in web application. Which method is vulnerable to attack? ·

Post - method can use for sending large amount of data.
There is no limitation on the number of Variables passed from the form.
This is a transparent way of transmitting variables to the webserver where hidden variable are always hidden ·

Get - method can use small scale of data.

2. List 2 configuration that can be made to the configuration file of an apache web server so that it become more secure

- Permission on server directory

3 List 3 configuration setting than can be made to PHP so that it become more secure ·

- Disable register globals and use E_STRICT to find uninitialized variables. ·
- Ensure that all file and streams functions (stream_*) are carefully vetted ·
- Disable allow_url_fopen and allow_url_include in php.ini

4. List 3 prevention measure that can be taken to overcome the Insecure direct object reference and Cross site request forgery vulnerabilities.

The prevention that can be taken to overcome the insecure direct object reference and Cross site request forgery vulnerabilities are input validation. Every input supplied to a system must be validated before it sends to be processed by server. Besides that, we must ensure that all user-supplied data is appropriately entity encoded before rendering. Next, we must use an index, indirect reference map or another indirect method to avoid direct references. This is to prevent exposure of direct object references.

5. Do the exercise under Improper Error Handling | Fail open Authentication Scheme, What is the vulnerability found in this exercise and can you prevent it from happening?

In this exercise, user can login without any password. There is no validation if the user left the password field blank (Due to the deletion by WebScarab). It will send directly to server. In order to prevent from this happening, the java code must be validated and enhances in security particularly on the authentication part.




Lecture 5 : Authentication & Access Control

::What is authentication ?

Verification of someone, that may have generated some data such as password, passport, signature or biometric.

::Tips of protection password :-

a) Do not let somebody have your password
b) Do not write your password anywhere, example in a piece of small paper.

::Tips of choosing good password :-

a) Use password hard to guess and easy to remember.
b) Not shorten from 6 characters and not in pattern of keyboard.
c) Using character and number.

Slide 4
¨
::Calculations on password

- Password population, N =rs
- Probability of guessing a password = 1/N
- Probability of success, P=nt/N

::Tips of guessing password

a) Try default password. (123456, abc123,tmadmin)
b) Try all short word. 1 -3 character
c) Use Dictionary word.
d) Collect information about user's.
e) Try phone number, NRIC number.


::What is Biometrics ?

Biometrics is a measurement of statistical analysis of biological data (unique)
Slide 23
¨

::List of biometric method :-

a) Vein recognition
b) Palm print
c) Gait Reconition (Gaya berjalan)
d) Body odour
e) Ear shape
f) DNA
g) Keystroke dynamic
Slide 29
:: Static VS Dynamic Biometric Method

Static - authentication based on feature that is always present. (retina, fingerprint)
Dynamic - Authentication based on a certain behaviour pattern.(keystroke.signature)

Lab 4 : Modern Cryptography

Lecture 4 : Program Security

Slide 7::Viruses and ”Malicious Programs”

a) Computer viruses has ability to replicate them self i
nto large number of computer. Spread by floppy disk and USB drive or nowadays is through internet.

b) Malicious programs may be installed by ha
nd on a single machine. But may built into software packages. It likes Trojan Horse, Traps Doors and Logic Bombs.

::
Slide 8Malicious Programs ::


Malicious program split into two:

* Need host program - Trap doors, Logic Bombs, Trojan Horses, Viruses.
*Independent - Bacteria, Worms.


:: Examples of malicious code

1) Trojan Horse - Slide 9 a program which performs a useful function, but also performs an unexpected action.

2) Virus - code segment that replicates and attach to existing programs.
Slide 9Transient - executes when the program that it is attached to runs.
Resident - stay in program when execute, stay till it trigger again.

3) Worm - program that replicates and copy the file/folder it locates.
4) Bacteria - program that replicates itself until fills up all spaces or CPU cycles.
5) Logic Bomb/ Time Bomb - malicious code that activates on an event.
6) Trap Door - written entry point, that cause unwanted users.
7) Spyware - Steal info, see web sites visited, see contents of files, popUp ads, slow down computer and crash the computer too.


Lab 3 : Classic Cryptography

1. What is the difference between monoalphabetic and polyalphabetic encipherment? Monoalphabetic cipher: Here a single cipher alphabet is used. Polyalphabetic cipher: Here a set of related mono alphabetic substitution rules is used.
2. Decrypt the following Caesar cipher text





Plaintext (by using shift-13 Ceaser Cipher): WEST ART THE ATTACK AT EIGHT PM TO NIGHT BEG I BY ATTACKING THE MAIN POST OUR OBJECTIVE IS TOTAL DESTRUCTION OF THE ENEMY BASED SPARE NO ONE AND ANYTHING DESTROY EVERYTHING ON YOUR PATH.

3. Decrypt the following Vigeneré cipher text




By using Google search kasiski method to help you in solving this problem

Plaintext: JULIUS CAESAR USED A CRYPTO SYSTEM IN HIS WAR WHICH IS NO REFERRED TO AS CAESAR CIPHER. IT IS AS HIT CIPHER WITH THE KEY