SQL injections or attack is the injection of malicious data into the database and getting important information for the database. This sensitive information can be used by running malicious code in the website. This is mainly a threat to web-based applications such as banking applications and other applications that involve transaction of money. Hence, it is essential that the developers know how to prevent SQL injection.
SQL injections are of two types, first order attacks and second order attacks. In case of first-order attacks, some data is injected in the database and this will run a code and reveal the information from the database. In second-order attacks, the data entered resides in the database and gives us some information about the database.
Here are some tips that will help you in preventing SQL injection.
Validate data properly:
- Any data submitted by the user should be validated properly. Proper validation methods will ensure that the user submits no malicious data.
- Consider that any data entered by the user is a threat to your database and conduct validation on any type of data, even if it is of least importance.
Do not use dynamic SQL queries if not necessary:
- If you use dynamic SQL queries in your application, the vulnerability of the data increases.
- Instead of using dynamic queries, use parameterized queries, prepared statements and stored procedures.
- They will increase the programming efforts but are always safe to use, so wherever possible use these queries in your application.
Test the code properly before deployment:
- Use automation tools to test the code before deploying it.
- Make sure that database testing is done properly, only then deploy the application.
- It is the most crucial part to test and should be tested by experienced testers at every stage of development.
Create patches as soon as you notice any vulnerability:
- Even if you test the code properly, it is likely that some bugs are left unfixed in the code.
- You may observe some problems with the application after deployment. It is essential that you create proper patches for such holes in the database, which makes the database vulnerable.
Use passwords to protect your application:
- In an attempt to keep the data in your application safe, make use of hashing passwords and encryption.
- You can also use connecting strings to make your data secure.
Limit user input:
- Do not allow users to enter any data and make request from the database unless it is very essential.
- You should always keep the number of user inputs minimum.
- You can limit the user input by escaping them using certain queries.
Keep the magic quotes variable off:
- While writing the code, make sure that the magic quotes variable is off i.e. magic_quotes_gpc variable is off.
- This will not give complete prevention from SQL injection but will minimize the risk of SQL injection.
Never use unnecessary functionalities:
- There are many unnecessary inbuilt functions and procedures in the database, which can give access of the database to the hackers.
- You should disable such procedures and functionalities that can be used by the hackers and get information from your database.
Following the tips given above, you can easily prevent your data from being leaked.