Security Analyst

2013-02-07T01:59:00.002-08:00

Address resolution protocol & ARP poisoning:

Address resolution protocol:

•Address resolution protocol, a network layer protocol used to convert an IP address into a physical address.

•A host wishing to obtain a physical address broadcasts an ARP request onto the TCP/IP network. The host on the network that has the IP address in the request then replies with its physical hardware address.

•There is also Reverse ARP (RARP) which can be used by a host to discover its IP address. In this case, the host broadcasts its physical address and a RARP server replies with the host's IP address.

•ARP stands for Address Resolution Protocol and it allows the network to translate IP addresses into MAC addresses.

Arp Poisoning Attack:

•When one host using IP on a LAN is trying to contact another it needs the MAC address of the host it is trying to contact.

•It first looks in it's ARP cache (to see your ARP cache in windows type in "arp –a" at the command line) to see if it already has the MAC address, but if not it broadcasts out an ARP request asking "Yo, who has this IP address I'm looking for?" If the host that has that IP address hears the ARP query it will respond with it's own MAC address and a conversation can begin using IP.

•In common bus networks like Ethernet using a hub all traffic can be seen by all hosts who's NICs are in promiscuous mode, but things are a bit different on switched networks.

•A switch looks at the data sent to it and tries to only forwards packets to its intended recipient based on MAC address. Switched networks are more secure and help speed up the network by only sending packets where they need to go.

•There are ways around switches though, Using a program like Arpspoof, Ettercap or Cain we can lie to other machines on the local area network and tell them we have the IP they are looking for, thus funneling their traffic through us.

Example:

•Basically, the Cracker is telling A's box that he has the IP that corresponds to B's box and vice versa. By doing this the Cracker receives all network traffic going between A and B. Once you have Arpspoofed your way between two machines you can sniff the connection with whatever tool you like (TCPDump, Ethereal, Ngrep, etc.) By arpspoofing between a machine and the LANs gateway you can see all the traffic it's sending out to the Internet.

2013-02-04T02:36:00.003-08:00

Encoding:

Encoding transforms data into another format using a scheme that is publicly available so that it can easily be reversed.
It does not require a key as the only thing required to decode it is the algorithm that was used to encode it.
Encoding is for maintaining data usability and can be reversed by employing the same algorithm that encoded the content, i.e. no key is used.
Examples: ASCII, Unicode, URL Encoding, Base64

Encryption:

Encryption transforms data into another format in such a way that only specific individual(s) can reverse the transformation.
It uses a key, which is kept secret, in conjunction with the plaintext and the algorithm, in order to perform the encryption operation.
As such, the ciphertext, algorithm, and key are all required to return to the plaintext.
Encryption is for maintaining data confidentiality and requires the use of a key (kept secret) in order to return to plaintext.
Encryption is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it.
Unencrypted data is called plain text ; encrypted data is referred to as cipher text.
There are two main types of encryption: asymmetric encryption (also called public-key encryption) and symmetric encryption.
Symmetric (or public-key) encryption: A type of encryption where the same key is used to encrypt and decrypt the message.
Asymmetric (or public-key) encryption: This uses one key to encrypt a message and another to decrypt the message.
Examples: AES, Blowfish, RSA

Hashing:

Hashing is used in conjunction with authentication to produce strong evidence that a given message has not been modified.
This is accomplished by taking a given input, hashing it, and then encrypting the sent hash with the recipient's public key.
When the recipient opens the message with their private key they then hash the message themselves and compare it to the hash that was given encrypted by the sender.
If they match it is an unmodified message.
Hashing is for validating the integrity of content by detecting all modification thereof via obvious changes to the hash output.
Examples: SHA-3, MD5 (Now obsolete), etc.

2011-01-28T04:12:00.000-08:00

Matriux:

Matriux is a live security operating system which consists of powerful and open source tools and free tools which can be used for various urposes like penetration testing, ethical hacking, cyber investigations, vulnerabitlity analysis, data retriveing and not only limited for this, can be used for other purposes.

It can also be used as a normal desktop systems.

With this matriux we can turn a normal system to a powerful penetration testing toolkit.

The open source tools can do the following ,

1.reconnaissance --which can gain information about an enemy or potential enemy

2.scanning

3.Debugger

4.Tracer

5.Fuzzer

It also includes general tools for multimedia and internet applications.

It can be used from a live environment like CD, DVD, USB Disk or it can also be installed directly in to hard disk in very few steps.

Finally i can say that it is much similar to Back track.

2011-01-10T04:32:00.000-08:00

SSL Renegotiation vulnerability:

Renegotiation is to negotiate new terms to replace old ones.

This occurs because server treats the client's initial TLS handshake as a renegotiation and thus believes that the initial data transmitted by the attacker is from the same entity as the subsequent client data.

The vulnerability involves a flaw in renegotiation and allows man-in-the-middle attackers to surreptitiously introduce text at the beginning of an SSL session.

Renegotiation allows one part of an encrypted connection to be controlled by another.

Step by step process for renegotiation:

1. Client starts TLS hand shake with the server, the attacker who is in the middle does not forward this hand shake packets. Let us consider this as session@1. Thus ot resemblance MITM attack.

2. The attacker negotiates a new session and performs a complete TLS exchange. Let us consider this as session@2.

3. The attacker sends application level commands over the previously established TLS session.

4. The attacker requests a renegotiation of the handshake process. Renegotiation is to negotiate new terms to replace old ones. Renegotiation may be activated due to different cipher requirements on different resources.

5. He then forwards handshake packets of the session @1 within the encrypted session @2.

6. The TLS handshake started i.e session@1 hold back by the attacker, is now being let to the server which performs a new TLS Handshake over the previously established encrypted TLS session @2.

7. The client holds now an authenticated session and sends requests containing the authentication credential (i.e. cookie). The attacker gets this request and appends the client request to its previous request and forwards to the server.

8. Finally merged request consists of the attacker request and the authentication credential from the authenticated client.

Authentication Gap in SSL Renegotiation:

Authentication gap in SSL is due to renegotiation during the negotiation process at which an attacker joins heterogeneous connections in a completely standards-compliant way. Web servers will combine the data they receive prior to renegotiation with the data they receive after renegotiation.

GET attacks are essentially trivial to execute. An application that only makes changes in response to POST requests will probably not be vulnerable.

Affected Versions:

SSL version 3.0 and newer version.

TLS version 1.0 and newer version.

Resolution:

1. Disabling renegotiation:

This cannot be configured easily, but the majority of web sites do not use renegotiation so disabling it won't be a problem.

2. Using a firewall :

To monitor the contents of all request headers to spot what seems like an embedded HTTP request. Good thing is that embedded request line will not be obfuscated, making it easier to detect.

Example:

GET /path/resource.asp HTTP/1.0------à attackers
Header: GET /index.asp HTTP/1.0
Cookie: 123455678796_jjoivcdf_@Dss----> clients

Scenario:

              sess1                                 sess2

  TLS client <--->  rogue TLS server (doing MITM)  <--->  victim MS IIS

Impacts:

This vulnerability is used to theft the credentials.

This is also useful to perform CSRF attack.

2010-12-09T03:58:00.000-08:00

DLL Hijacking:

DLL –Dynamic link library are set of functions, and small programs that are used by large programs that are running in the computer. It’s Microsoft implementation of shared library where the data in the library can be shared by any module within the computer. These functions are responsible for the larger programs to communicate with external devices like printer, mouse etc.

They are not loaded into Random access memory together with the application so the added advantage is memory is saved in RAM. Whenever a DLL is needed it is loaded and run.

For example: A user is editing Microsoft Word document, If and only if the user decides to print the document, then the printer DLL file gets loaded into RAM and run, until that the DLL file does not needs to be loaded.

All DLL file will have .dll extension. All windows and some non-windows applications rely on DLLs as a part of their functionality.

So by this we can say that along with the DLLs built in windows, developers also create DLLs that contain functions which will be used by the application. All the DLLs used by the application are packaged and installed within the application.

DLL hijacking:

When the DLLs are packaged and installed within the application, there is a need to developer to specify certain path at which the packaged DLLs are to be executed but, this is not possible i.e application does not have statically defined path. Then it searches for the directory it was executed from, and then searches the system directory and then placed.

To get an idea of how is it occurred take the above scenario with the below explaining below, an attacker is executing an application that must dynamically search for required DLL when loaded, the application immediately searches the path it was executed from and then finds a DLL that matches. In the Windows system directory, the real DLLs associated with the application are located. The DLL which are placed in the directory with the application is that which has been modified by an attacker to allow remote command shell access into the system.

However, the application never gets the real DLL because it matches.

2010-11-25T04:06:00.000-08:00

FIREWALL:
A wall constructed to prevent the spread of fire.
It is hardware / software or combination of both which is used to prevent unauthorized or unwanted communication between trusted and un-trusted networks. It allows the traffic based on rules, IP address, ports, etc.

Firewalls are frequently used to protect the private network (Intranet), from accessing by unauthorized internet users i.e, private networks which are connected to internet can be accessible by any unauthorized users, but if a firewall is used it inspects each message and blocks if that does not meet the Security rule.

Usually data is transferred in the form of “packets” from one system to other in a network, Firewall inspects each individual packet from either side and determines whether to allow or block the packet. In some cases it even asks the user about allowing the packet.

A Packet consists two types of data 1.Control information 2. User data. The first provides data the networks need to deliver the user data i.e source and destination address, sequencing etc.

Basically there are three categories they are

Hardware firewall:

1. Hardware firewalls are important because they provide a strong degree of Protection from most forms of attack coming from the outside world.

2.They can be effective with little or no configuration, and they can protect entire network i.e every machine on a local network.

3.More expensive and harder to configure.

4.This follows a technique called “packet filtering”
(Packet filtering: Packet filtering is the blocking of data packets as they pass through a network interface when the packet does not meet security criteria.)

1.Hardware firewall examines the header of the packet for its source and destination address which are compared to predefined rules which are described by the user and then determines whether to allow or block the packet.

2.The more advanced technique is Statefull packet interface which looks at packet actual origin i.e did it come from internet or from local network.

3.Because it's not physically on your machine, a hardware firewall is less vulnerable than a software firewall.

Software firewall:

Software firewall when installed on a computer, you can specify which applications are allowed to communicate over the Internet. Programs that aren't explicitly allowed to do so are either blocked or else the user is prompted for confirmation.

Most of the software firewalls have user defined controls which are used to design their own security laws. A software firewall will protect your computer from outside attempts to control or gain access your computer.

A good software firewall is, which runs in the back ground of your machine and uses only a small amount of system resources.

Best thing is to use a combination of hardware and software firewall.
Actually a Software firewall in installed on one machine and it acts as proxy to other computers.

Firewall Technique:

Packet filter: It is blocking of data packets as they pass through a network interface when the packet does not meet security criteria.

Packet filter probes each packets passing through network based on the user defined rules.

Security Testing And Network Concepts...

2010-11-18T22:01:00.000-08:00

NMAP: NETWORK MAPPER:

NMAP is open source utility (A company that performs a public service) that is used for security auditing (Examine carefully for accuracy with the intent of verification) which is used to know the hosts and services on a computer network i.e application name and version, firewalls, operating system.

By default nmap performs an SYN SCAN which works against any compliant TCP stack .(TCP SYN SCAN uses common methods of port-identification that allow nmap to gather information about open ports without completing the TCP handshake process. When an open port is identified, the TCP handshake is reset before it can be completed. This technique is often referred to as "half open" scanning.) When it is having privileged access on host then TCP SYN SCAN is used by default if scan type is not specified on nmap command line.

---If nmap receives an acknowledgment to a SYN request, then the port is open. Nmap then sends an RST to reset the session, and the handshake is never completed.

---The SYN scan is a common scan when looking for open ports on a remote device, and its simple SYN methodology works on all operating systems. Because it only half-opens the TCP connections, it's considered a very 'clean' scan type.

---The TCP SYN scan only provides open, closed, or filtered port information. To determine operating system or process version information, more intrusive scanning is required, such as the version scan (-sV) or the operating system fingerprinting (-O) option.

It can be used to scan thousands of ports and clearly differentiate between open, closed ports. Irrespective of this it divides ports in to six states.

---“Open” : an application on the target machine is listening for connections/packets on that ports i.e an application is actively accepting TCP connections ,UDP datagrams on that port. It means that each open port is avenue for attack. It is the duty of an administrator to close or to protect them by using firewalls.

---“Closed” : It is not that all closed ports are safe. They are even accessible i.e, it receives and responds to nmap packets but there is no application listening on it and it shows that the ip address of the host. Closed ports may be opened at any time. So administrator should block such ports with a firewall then they will appear in a filtered state.
Hence, Closed ports have no application listening on them, though they could open up at any time.

---“Filtered”:Filtered means that a firewall, filter, or other network obstacle is blocking the port so that Nmap cannot tell whether it is open or closed. Filtering can be done by using dedicated firewalls or some host-based firewall software.
Open ports cannot be determined by namp, because packet filtering prevents its investigation (probe) from reaching the port. Nmap provide very little information about this ports, sometimes they respond with ICMP error messages. But filters that simply drop investigation are more common which makes the nmap to retry, which slows down the scan.

---“Unfiltered”: This means that a port is accessible, but unable to determine whether it is open or closed. As the port is accessible there is a chance for an attacker to use this, so scanning unfiltered ports by other scan types may determine the state of port.

---“Open / filtered”:Whenever open ports does not respond to Nmap, then Nmap places as open or filtered i.e, lack of response from the host means that probe of Nmap has been dropped by packet filter or any response arosed.

---“Closed / filtered” :Nmap is unable to determine whether a port is closed or filtered. It is only used for the IP ID idle scan.
---In addition to this nmap can also provide information about MAC address, device types, reverse DNS names.

2010-08-10T01:24:00.001-07:00

1. What is Scenario Testing (in two lines)?

Scenario testing uses scenario tests which explains the other person to think practically about how the program is used by the end user with different attitude.

2. What are the benefits of Scenario-based Testing?

It helps in understanding the test case by imagining the situation.

It helps to stimulate the other person in such a manner that he will believe it.

As it is a story based it can easily understood by the second person.

3. How can a tester identify scenarios for a given application?

It depends on the identifying a test case and framing a story on that testcase, so it completely depends on the persons attitude and skill to frame a story.

4. Identify at least two scenarios in any application of your choice.

1. Funds transfer (Banking application):

Am having an account with amount 500, I want to transfer it to one of my friend. I have entered all the details and clicked ‘ok’, it then should removes 500 from my account and then should add it to my friend account. At this point a success message is send to the user, the transaction is not still completed, suddenly power fails, then what happens? Is the transaction lost or remains and proceeds after the power on.

2 Funds transfer (Banking application):

In my account am having Rs 20,000/. All my account details are known to my brother. I went to shopping and bought articles of RS 20,000/. I have given my card to the shopkeeper, he is ready to swap the card, on the other side my brother used to transfer the whole 20,000 to my dad’s account because of some reason by using online banking. If both the transactions are gone at the same time… then it is a scenario based test case. But it never happens. This type of testing is called concurrency testing.

What are Product based and Service based companies?

2010-06-11T02:28:00.000-07:00

PRODUCT BASED COMPANIES:

What is a product?

àA product is anything that can be offered to a market that might satisfy a want or need of market. Product may refer to a single item or unit, a group of equivalent products.

What are product based companies?

àA product based companies are those who will have their own products. They develop the product according to market needs. They will collect the requirements from market as well as their research team will have their own opinions of requirements and then they develop the products. To simplify, we can say product-based companies make a specific product and try to market it as a solution.

àThese products are used by the other companies by paying money to these companies. So the products which are going to be used should meet the maximum user needs.

àProduct companies invest in R&D, they take chances, and in they should have the ability to know “what” to build without somebody telling them to.

àTo speak frankly, no company can simply build and sell products without providing services around them.

àThey are mostly experts in developing a fixed kind of product. They mostly analyze the future requirements of the market.

Example for product based companies:

Microsoft, Sun, Oracle, Motorola, Yahoo etc…

àBut Apple, IBM, Sun - all develop products and provide services around them.

SERVICE BASED COMPANIES:

What is a service?

àWork done by one person or group that benefits another, it can also be provision of assistance to customers or clients.

What are service based companies?

àService based companies are those who will develop products for other clients or companies according to their requirements. These companies depend on client. Service Based Company will be involved in the development of Application which will used to serve the various sectors such as Insurance, Health care, Retail, Banking etc.

àAgain service based companies can be product based or project based. They collect all the requirements of the product and they have to full fill the client’s requirements.

àServices companies constantly innovate to remain competitive.

àThe challenge for both the companies will change but service based companies does not own intellectual property, but Product Company does it.

Example for Service based companies:

Infosys, Mahindrasatyam, Wipro ,Cognizant.

àThese all provide services to other organizations like banks, health organizations, institutions, etc

*********************

àPeople working in Product based companies should have abstract ideas, they want the people who uses his/her mind creatively. But people working in service based company must have technical skills and ideas which will fulfill the requirements.

àProduct based companies needs more creative people than service based companies, because product based companies does not require to fulfill any client’s requirements. They should have creative ideas and thoughts about the market needs and they have to fulfill those needs.

àSo we can say that people working in service based companies must have the ability to listen very carefully.

2010-06-07T01:58:00.000-07:00

Captcha:
-------------

In many registration forms to complete registration

process,we find a figured letters which should be typped by

seeing with naked eye and which cannot be coppied.

Not only in registration forms but also during

passsword recovery we find this.Which is called as CAPTCHA

Why?and for what purpose it is used?

CAPTCHA(Completely Automated Public Turing Test To Tell

Computers and Humans Apart)is a test used in computing to say

that the response is not generated by any computerised tool.

Why is Captcha used?

Many companies provide free e mail services.To abort the

success of such organizations there is a chance for other

organization to mis-use those email services by using some

computerised tools. For example there is a registration form

which has no of fields to be entered.There are some tools which

can enter the values into fields simultaneously, and can create

lakhs of emails with in very few minutes,this will abort from

creating new emails for the other users.

Solution for this problem:

The solution to this problem was to use CAPTCHAs to

ensure that only humans obtain free accounts. In general, free

services should be protected with a CAPTCHA in order to prevent

abuse by automated scripts.

Different types of Applications

2010-06-01T22:29:00.000-07:00

CLI----COMMAND LINE INTERFACE APPLICATION:
--------------------------------------------------------------

1.By using COMMAND LINE INTERFACE we can type commands in console window and can interact with computers operating system and we can perform some specific tasks.

2.After a command is entered system merely waits for the user to conclude by pressing enter, then command line interpreter receives and executes the requested command.

3.A great advantage to a CLI is that you can always see what you did — whereas with a GUI, if you aren't paying attention when your hand slips, you may never know what happened.

4.When CLI application is intialised and processing of transactions are completed the application must be properly disconnected from the datasource and free all the resources.

5.It has no icons or pictures, and often is so simple that even a mouse will not work — it relies on the keyboard

.
6. In some applications, such as MATLAB and AutoCAD, a CLI is integrated with the GUI, with the benefits of both.

7.CLIs are also popular among people with visual disability, since the commands and feedbacks can be displayed using Refreshable Braille displays.

Example: Visual studio command prompt.
Windows power shell.
Cobol

GUI---GRAPHICAL USER INTERFACE APPLICATION:
----------------------------------------------------------------

1.A program interface that takes advantage of the computer's graphics to make the program easier to use.this can avoid the user from learning complex command languages.

2.Some of the basic components of GUI are pointer,icons.windows, menus.

3.The first graphical user interface was designed by Xerox Corporation's Palo Alto Research Center in the 1970s, but it was not until the 1980s

4.By the emergence of the Apple Macintosh graphical user interfaces became popular. One reason for their slow acceptance was the fact that they require considerable CPU power and ahigh-quality monitor, which until recently were prohibitively expensive.

5.In addition to their visual components, graphical user interfaces also make it easier to move data from one application to another.

Example: Windows7,Mac Os

THICK CLIENT AND THIN CLIENT:
THICK CLIENTS :

1.These are the networks which typically provides rich functionality independently of the central server.

2. In designing a client–server application, a decision is to be made as to which parts of the task should be executed on the client, and which on the server. This decision can crucially affect thecost of clients and servers, the robustness and security of the application as a whole, and the flexibility of the design to later modification or porting.

THIN CLIENTS:

These are designed small and bulk of data processing occurs at server side, they require constant communication with server.They provide desktop environment. Ex...schools,hospitals,airticketing,railway tickiting.

CLIENT-SERVER APPLICATIONS:
-----------------------------------------
1.It is a distributed application at which client requests for a service from service provider,server.

2.While developing this type of applications developer must consider team environmenta and long term maintainenece.

3.Sockets involve a major place in client server application.

4.In a network, the client/server model provides a convenient way to interconnect programs that are distributed efficiently across different locations.

5.This is the way to connect computers which are geographically away and we can make transactions.

**Protocols:
a)TCP/IP:
The program which uses TCP must follow these rules:

The server side would follow these steps:
Create a socket.
Listen for incoming connections from clients.
Accept the client connection.
Send and receive information.
Close the socket when finished, terminating the conversation.

In the case of the client, these steps are followed:

Create a socket.
Specify the address and service port of the server program.
Establish the connection with the server.
Send and receive information.
Close the socket when finished, terminating the conversation.

b)HTTP (HyperText transfer Protocol): used on the World Wide Web (WWW) for transfering web pages and files contained in web pages such as images.

c)FTP (File Transfer protocol): employed for transfering files from one machine to the other.

d)SMTP (Simple Mail Transport Protocol): used for email.

e)Telnet Protocol: Used to open telnet sessions.

Examples: Online banking,
Sql server management studio.

LEGACY APPLICATIONS:

-------------------------------

1.Legacy means outdated, legacy applications are those which are written for earlier operating system or hardware or platform but those are running in current technology.

2.We have to keep the legacy application running while converting it to newer.

3.Even after running under current technology they must be capable of running at platform they were developed for.

4.With many new tools, legacy databases can be accessed by newer programs.

5.Where it is impossible to replace legacy systems through the practice of application retirement, it is still possible to enhance them.

Examples:Windows 3.1and DOS running under windows vista
NASA (NASA's Space Shuttle program still uses a large amount of 1970s-era technology)
MAINFRAMES.

INTRANET/INTERNET:
----------------------------

INTRANET:

-----------------
1.An intranet is a network that can share any part of an organization's information or network within that organization.

This is a network which is not available to outside world.

2.Refers to a network within an organization. Sometimes the term refers only to the organization's internal website, but may be a more extensive part of the organization's information technology infrastructure

.
3.Intranet uses same concepts and technologies which are used for the Internet, such as client–server computing and the Internet Protocol Suite (TCP/IP).

4.As this is with in organization it can only usable by employees.

5.Benefits of intranet---Communication,cost-effective,immediate updates,cross-platform compatability,time, business operations,knowledge of your audience.

INTERNET:
-----------------
1.Internet is a global network that connects millons of computers which are geographically separated.

2.It provides online services like sharing of data

3. Internet and the Web are not same.The Internet is a global data communications system . It is a hardware and software infrastructure that provides connectivity between computers.

4. In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs.

5.E-mail is an important communications service available on the Internet.
For both intranet and internet HTTP protocols of web which are to be followed for transfering files on www.

A browser is an HTTP client and server is an HTTPserver.

Examples:
Banking, E-commerceapplications, shopping, online ticket booking.

WEB-SERVICE Application:
-----------------------------------

1.Web Services are a new breed of Web applications.Web applications are those which provide services by using network such as internet/intranet.

It can also be described as computer based software application that is hosted in browser control environment.

They are self-contained, self-describing, and modular applications that can be published, located, and invoked across the Web.

2. The Web Services Framework utilizes the HTTP protocol (as standard Web Application) in conjunction with XML, SOAP, WSDL and UDDI technologies.

3.Web service call composer or Web Service Tester used for testing web service apps.

4.Recent revolution in technology is service oriented approach or web service model which business over web as the e –commerce application..

Example:Online Bookstore Web Services Application, all e-commerce applications.

2010-06-01T22:27:00.001-07:00

Different definitions for Software testing:

Software testing is an art, science, discipline to measure the quality of software before delivering it to customers.

5. set of activities conducted with the intent of finding errors in software.
process of verifying that a program functions properly.

2.Testing automated, in part or in full, by another program.

3.Software testing is an investigation conducted to provide
stakeholders with information about the quality of the product
or service under test.Software testing also provides an objective,
independent view of the software to allow the business to appreciate and
understand the risks at implementation of the software.

4.Software testing is any activity aimed at evaluating an attribute or capability
of a program or system and determining that it meets its required results.

5.A primary purpose for testing is to detect software failures so that defects
may be uncovered and corrected. This is a non-trivial pursuit. Testing cannot
establish that a product functions properly under all conditions but can only
establish that it does not function properly under specific conditions.[12]

6.Software testing is used in association with verification and validation:

Verification: Have we built the software right? (i.e., does it match the specification).
Validation: Have we built the right software? (i.e., is this what the customer wants).

7.Testing can be used as a generic metric as well. Correctness testing and reliability
testing are two major areas of testing. Software testing is a trade-off between budget,
time and quality.