Posts Tagged ‘Infosec’

This post does not make you hacker overnight, or by this you cannot hack a website, this is not a shortcut to become a security tester. This article is purely for helping individuals in building secured applications.

If you are from infosec, you might be tired of listening to people asking, is application good to go live, can I push my code to production? Below are some of the easy steps for developers for developing a secured application and this would reduce efforts and time of security team on vulnerability assessment and penetration testing. It is always advised to have a proper code with certain validation and verification.

1. Authentication:

a) Don’t hardcode credentials: Credentials should not be saved within the application. To some extent it might be useful during development stage but strongly advised not to be saved within the application code.

b) Store Database Credentials Securely: The credentials must be stored in a centralized location as a separate database for which authentication is required.

c) Error handling on invalid credentials: Error Messages on invalid credentials for authentication must be clear and must not reveal any sensitive data against username enumeration or other available fields.

d) Account lockout against bruteforce attacks: Account lockout policy needs to be implemented to safeguard against brute force attacks for both the login and forgot password features. The account should be locked for a certain period of time say 24/48 hours or until manually unlocked from the application support

e) Browser memory: Credentials should not be retained in browser memory after logout. The credentials should be encrypted with base64 or any secured hashing mechanism.

2. Authorization

a) Access control checks: Make sure that there is a separate mediatory between different privileges with a principle of common security assistance on the application.

b) Least Privileges: Users of an application should not provide root access instead minimal privileges could be given. If not explicitly allowed then access should be denied.

c) Don’t use direct object references: Do not allow direct referencing to any files or parameters that can be manipulated to grant access to the resources. Privileged access should be assigned based on individual user identity.

d) Validated redirects: An attacker can get access to private content without authentication, if redirection are not validated properly.

3. Input Validation and Output Encoding (Text Fields)

a) Output Encoding: All output operations must contextually encode data before displaying it on browser.

b) Set Encoding in the Application: For every page in your application set the encoding using HTTP headers or meta tags within HTML. This ensures that the encoding of the page is always defined and that browser will not have to determine the encoding on its own.

c) Prefer White-lists Over Blacklists: All the input fields should have input validation. White listing input is the preferred approach. Data that meets a certain criteria must be accepted.

d) Tokens against Forged Requests: Applications must embed random token that is not known to third parties into the HTML form for preventing CSRF (Cross-Site Request Forgery) attacks. This CSRF protection token must be unique to each request. This prevents a forged CSRF request from being submitted because the attacker does not know the value of this random token.

e) File Uploads: While accepting files from the user make sure to validate the size of the file, the file type, the file-name, the file contents and where is it going to save as well as ensuring that it is not possible to override the destination path for the file.

f) Parameterized SQL Queries: SQL queries should not be created dynamically using string concatenation. Similarly, the SQL query string used in a bound or parameterized query should never be dynamically built from user input.

g) Terminate/abort invalid inputs: This is a safety and final strategy on unaccepted characters that occur as input, but if implemented poorly it might lead to Denial Of Service attack in which attacker can flood the system with unexpected inputs, forcing the system to expend scarce processing and communication resources on rejecting it.

4. Session management

a) Session fixation: Session tokens must be changed during login and must have different tokens for logged in and logged out states.

b) Session variables invalidation: Session variables should be invalidated in the server after logout or session timeout after a certain period of idle session.

c) Unique session variables:  Session variables must be unique and should not be reused for different accounts.

d) Strong session variables: Session variables should be random and must be of certain length which is not easily guessable by the attacker.

e) Secure cookie variables: Usage of secure cookie attributes i.e., Httponly and Secure Flags. The cookies should be set to exact domain and path and the cookies should not be shared with other sub domains.

5. Communication Protocols

a) SSL: Clear text protocols such as HTTP is always prone to MITM (Man In The Middle) as an attacker can intercept requests in the network level hence SSL is recommended during authentication and post login pages.

b) Disable HTTP: Resources accessible on secured channel such as HTTPS must restrict access with clear text protocols such as HTTP

c) Salted passwords: Passwords must be stored using a secured algorithm and iteratively hashing with a random salt added to hash  makes more stronger to crack

d) SSL Certificates: SSL certificates used must be from a reputed CA signed with secure exchange keys and ciphers.

6. Logs

a) Maintain logs on all privileges: This includes all authentication activities, all privilege changes, administrative activities, access to sensitive data.

b) Secure your logs: Logs are to be saved carefully and maintained on a secure server against tampering to avoid from loss and logs should be maintained for a specific duration according to industry policies.

c) Improper logs: Maintaining appropriate logs and storing them are the important part of logging management. Sensitive information should not be part of logs and the entire log needs to be encrypted in certain situations.

7. Reset password

a) Once reset password link is used, link should be expired for the next use.

b) Till the user resets password, the previous password should not be disabled.

c) Even if the link is unused the reset password link needs to be expired within a defined time say 48 or 72 hours.

d) Reset password link should be over an SSL

e) Old/previous password reset link should be expired once new password link is generated.

f) Token used in reset password link should be mapped to the users email ID and should not be used to reset password of another user.

g) Token should not be sequential or easily guessable or a short one. It should be minimum of 16 characters so that it is not easily brute forced.

h) Password policy should be maintained on reset password page.

8. Error Handling

a) Generic error messages: Display generic error messages to the user, error messages should not reveal details about the application like technology used, internal IP or path, and stack-overflow errors.

b) Framework related errors: All framework generated errors must be generic or messages can be customized so that sensitive information about the framework is not revealed.

c) Unhandled exceptions: Exceptions are strictly advised to handle errors either at client or server side. It is good to have ‘finally’ code block for all unhandled errors with generic error message.

References:

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Infographic: State of Security Testing by Nagasahas Dasa and Santhosh Tuppad

Infographic: State of Security Testing by Nagasahas Dasa and Santhosh Tuppad

Recently, I authored an article at TestingCircus e-magazine and I like to publish the same on my blog so that I can reach out to my readers who are not subscribed to testingcircus or couldn’t read due to whatsoever reason(s).

Thanks to Mr. Santhosh Tuppad for encouraging me to write this article and Mr. Ajoy Singha for providing me an opportunity to write for TestingCircus and I am looking forward to continue my contribution to TestingCircus e-magazine by writing, you can find my article in the following link  http://www.testingcircus.com/testing-circus-2013-september-edition/

Without much ado, here I present you with my article.


There is no wrong way to start hacking, everything is right way and I have my own way. Whatever your style of hacking is, make sure it’s consistent. If you are starting out today you can be benefited based on your skill sets. Don’t learn to hack, hack to learn.

Well, coming to the point how did I start hacking or how did I land up here, It was in the year 2008. I was in my 2nd year diploma where one of my friends was trying to download videos by searching on Google. In 2008, getting a video to your local machine was one of the biggest achievements for people of my age. My friend showed me how to get the videos from Google, by extracting only videos from the vast search results. He asked me to enter some string along with the search query.

Filetype: avi <Search Query>

He didn’t know what it was, and he told that he came to know about it through his senior. Ok!! As I am very much interested in computer technologies, I tried to find out what they are. I referred to many articles and found that they are called as GOOGLE DORKS. I even came across some of the terminologies like White, Black and Grey hat hackers. During this phase, I got a common response from whoever I asked about hacking, which was “Hacking is very difficult and I don’t know anything on it except that it is illegal”.

But, it is not illegal as I told you before. There are 3 categories of hackers:

  • Black Hat Hackers
  • White Hat Hackers
  • Grey Hat Hackers

Black Hat hackers are those who perform undercover hacking for malicious reasons and also with intent to harm others, such people can also be referred to as ‘crackers’.

White Hat hackers are those who perform hacking for legitimate reasons and use their skills and knowledge for good, e.g. IT Security technicians testing their systems and researchers testing the limitations of any software.

Grey hat hacker is a combination of a black hat and a white hat hacker. A grey hat hacker may surf the internet and hack into a computer system for the sole purpose of notifying the administrator that their system has a security defect.

According to a survey the most common technique of hacking a website is SQL Injection. SQL Injection is a technique in which hacker insert SQL codes into web form to get Sensitive Information like (User Name, Passwords) to access the site and deface it. The traditional SQL injection method is quite difficult, but nowadays there are many tools available online through which any script kiddie can use SQL Injection to deface a website. Because of these tools, websites have become more vulnerable to these types of attacks. Some of the tools used for SQL Injection are mentioned in this article. However, as I know nothing is bug free and there will be exploits every minute/hour.

Some of the tools which help in finding the vulnerabilities are discussed below:

1.      Wireshark is also known as Etherea. It is one of the most powerful tools in a network security, as a network packet analyzer on any network. It is used to capture each packet sent to or from your system to the router. If you’re capturing on a wireless interface and have promiscuous mode (Admin/super user) enabled in your capture options, you’ll also see other packets on the network sent from different nodes. This also includes filters ex: DNS, TCP, UDP, ip.addr etc), color-coding, capturing packets and other features that let you dig deep into network traffic. Wireshark is an extremely powerful tool; this is just scratching the surface of what you can do with it. Professionals use it to debug network protocol implementations, examine security problems and inspect network protocol internals. To get this position, it takes a fair amount of practice. It takes practice to know how and where to capture right data, filters to use, and how to interpret the data.

People willing to learn can use this link to get sample captures on Wireshark to get experience hands on this http://wiki.wireshark.org/SampleCaptures

2.      Fiddler is an open source web debugging tool which captures all the traffic between your computer and the internet, it also acts as proxy between the browser or any application on the local machine and the internet say, all the traffic flows through the fiddler and the requests can be altered and the altered request is been sent to the server. In simple words fiddler sits between HTTP client that is the browser and the HTTP server.

Normally it would be configured with all the browsers being used on a particular machine or you may have to manually configure the browser to capture all the traffic in/out of our machine.

Fiddler can also be used to find the statistics, inspect the request or the response and can even act as an auto responder and is capable of sending request from the fiddler wit out any browser. Fiddler is designed in such a way that it capability to run API’s through composer functionality and can even right some scripts which can be helpful for check automation and has the capability to decrypt HTTPS traffic.

3.      Nessus, the first public release was in 1998. Nessus was an open source vulnerability scanner, recently nessus turned into a paid tool. This tool is used for scanning both web application and network, Network can be either internal or external IP/Network. Nessus is designed to automate the testing and discovery of known security problems. Allowing system administrators to correct problems before they are exploited.

Nessus uses a client server design that allows the user to set up one server that has multiple nessus clients that can attach and initiate vulnerability scans, where servers can be placed at various strategic points on a network allowing tests to be conducted from various points of view.

Nessus security checks vulnerabilities and database is updated on a daily basis which could be retrieved to cross check the database with the command “nessus-update-plug-ins”.

4.      IBM Rational AppScan is an automated web vulnerability scanner which helps in finding the vulnerabilities quickly and effectively, even a svan (semi technical person) can also use the tool and find vulnerabilities.  Using IBM app scan, we can decrease the risks in web application attacks and data breaches. It helps in testing the web application either on production site or on any staging sites which can ensure that it checks for web attacks.

Basically in IBM AppScan once you add a web app to test for its security the initial step is to crawl all the pages/links on that application which are allowed to be crawled based on robots.txt

Basic functionalities of IBM AppScan are

  1. Gives the larger coverage of test report
  2. It mainly concentrates on top 10 OWASP (Open Web Application Security Project) web application vulnerabilities.
  3. Accurate and advanced scanning algorithms used hence less false positives
  4. Recommendations, Which I personally like here, It gives us description of each vulnerability found and the risk involved in not fixing it.

As we all know automated scanning is not perfect all the time and is not advisable to completely depend on automated scanner, hence they have provided a manual scanning for any vulnerability found to give the perfect solution without false positives.

IBM app scan is a paid tool and it has a trial version as well if you are interested in exploring the application.

5.      Nmap, also known as “network mapper”, it is an open source application which helps in quickly scanning different ranges of devices such as desktops/laptops or any mobile devices and provide valuable information about the devices which are connected to a particular network. Nmap is available for all the platforms where it can be operated in 2 ways, command mode and GUI mode but most people prefer command mode for its advanced features but requires technical knowledge.

Nmap uses raw IP packets to determine what hosts are available on the network (Host Detection), the services that are enabled, the operating system and version, using TCP SYN or a TCP Connect ping to gather active hosts. Nmap is used by security researchers and hackers who want to find the weakness and exploit them.

Nmap can provide different types of scans, where some are more aggressive and some are simple, designed to be stealthy and scan undetected. Depending on the type of scan performed, different information can be discovered; some of the scans are Ping, SYN Stealth, UDP Scan, IP Protocol Scan, ACK Scan, RPC Scan, List Scan etc.

6.      Havij is an automated SQL Injection tool that helps hackers or security researchers to find and exploit SQL Injection vulnerabilities on a web page on a vulnerable web application, using Havij user can access database, retrieve DBMS users and  password, dump tables and columns, fetching data from the database, running SQL  statements and  executing commands on the  operating system.

Hackers use Havij along with vulnerability scanners such as IBM AppScan or Web Inspect, vulnerability scanners find vulnerabilities but not help you in actual exploitation and that’s where Havij showcases its functionality.  In other words, vulnerability scanners will help you in finding list of vulnerable webpage’s whereas; Havij helps you with the access to the database for entire exploitation.

Once URL is feed to the Havij, it comes up with a list of databases being used, version, and db-name’s. Later selecting a particular database we can drill down to tables, and then to columns and even to the actual data. Passwords would hashed usually, there are set of de-crypter’s  associated with the tool which help user to decrypt the hashed password, it is also associated with an algorithm which helps users to find the admin page of a particular web application. In simple words it’s more useful for hackers than security researchers.

7.      SQLMap is one of the most popular and powerful open source SQL injection automation tool, which is built on python and can run on any platform if python is installed in it.

Giving a vulnerable URL, SQLMap can exploit the database and provides with sensitive information like extracting database names, tables, columns, all the data in the tables etc. It can even read and write files on the remote file system under certain conditions.

We can run this application only on command mode and doesn’t have an interface, and has simple commands to extract information from the database.