Understanding how sql injection attacks work

Based on our analysis of 1599 WordPress plugin vulnerabilities reported over 14 months, SQL Injection vulnerabilities are the second most common vulnerabilities found in WordPress. Data recovery ntfs If you’re able to avoid writing XSS and SQL injection vulnerabilities, you will have removed the risk of writing 65% of all vulnerabilities you might ever accidentally create.

Most useful WordPress plugins have some kind of interaction with the database.


Database error User input is frequently sent to the database, either because it needs to be stored in the DB, it needs to modify something in the DB, or because it is being used as part of a SELECT statement. Database functions If user input is not properly validated and escaped, an attacker can replace that user input with commands they can send directly to the database.

There are two kinds of SQL injection. Top 10 data recovery A ‘classic’ SQL injection vulnerability is one where unfiltered user input lets an attacker send commands to the database and the output is sent back to the attacker. Database job titles A ‘blind’ SQL injection vulnerability is when the attacker can send commands to the database but they don’t actually see the database output. Data recovery linux live cd What is the impact of a SQL injection vulnerability?

In the following video, we create a WordPress plugin that contains a SQL injection vulnerability. S pombe database Then we demonstrate how to attack our test website and exploit the vulnerability. Database usa We get a list of databases we have access to, view the tables in the database and download sensitive personally identifiable information (PII).

This is a clear demonstration of the devastating impact that SQLi vulnerabilities can have on a business. Data recovery pro license key We encourage you to watch the video and pause where necessary to view source code or command details.

The above code is an example of a SQL injection (SQLi) vulnerability. Data recovery on android It is an SQLi vulnerability because the user input in $_GET[‘id’] is sent directly to the database without sanitization or escaping. Icare data recovery 94fbr This allows an attacker to send commands directly to the database.

The database output is then sent directly back to the user’s browser. Image database Because the output is sent to the browser, this makes the vulnerability a classic SQLi vulnerability, as opposed to a blind SQL injection vulnerability, which is discussed below.

Using this vulnerability an attacker can send commands directly to the database. Database web application These include SELECT commands to download your entire database including any user personally identifiable information (PII). Database graphic In some cases it also includes INSERT and UPDATE commands to create new user accounts or modify existing user accounts.

To fix the above vulnerability is relatively easy. In databases a category of data is called a In WordPress you simply need to use the prepare method which will automatically sanitize and escape any data you send to the database. Database wordpress The above code can be modified as follows to remove the SQLi vulnerability:

Note that we use the $wpdb->prepare() method to escape the data we are sending the database. Note 2 data recovery It has a syntax that is similar to the sprintf() function which allows you to use placeholders. Tally erp 9 data recovery A %d is an integer, %f is a float (or decimal) and %s is a string (or text). Database erd If you are using %s as a placeholder, you don’t need to include quotes as these are added automatically. Database google docs How a Blind SQL Injection Works

In the above example, raw unsanitized user input is sent directly to the database by concatenating the $_GET[‘id’] variable directly to the SQL query. Database 5500 To fix this vulnerability, you would simply use the prepare() method as above to sanitize and escape any database input.

The difference here is that the output is never sent to the browser. Data recovery kit A blind SQLi vulnerability is just as serious as a regular SQLi vulnerability because an attacker can in some cases easily insert or update data in your database. Database meaning The difference is that it becomes more difficult to extract data from the database because the attacker can’t see the output of the database because it is not written to the web browser. Gale database Time based blind SQL attacks

There are generally two ways an attacker extracts data from a database using a blind SQL injection attack. Data recovery pc The first is using a time based attack. Data recovery easeus Lets assume that, using the above SQLi vulnerability an attacker can send any command to the database, but they can’t see the output. Top 10 data recovery software They can only see the resulting web page.

An attacker might ask the database a question like “Does the first letter of the first admin account start with ‘a’? If it does, then sleep for 5 seconds and if it does not, don’t sleep at all. Database oracle If it takes less than 5 seconds for the web page to be generated and return to the web browser, they know that the admin account does not start with the letter ‘a’ and they move on the the next letter, ‘b’ and ask the same question.

Using this technique, an attacker can launch a time based attack on a website and determine the names of admin accounts and they can extract hashed user passwords.

What this SQL says is “select the post_title where the post ID is 1, but merge in a query that will take a lot of time if we guess that the user account with ID 1 (which is usually an admin account) has the letter ‘a’ as the first letter of the username.”

When this query is run, if the page takes a long time to load, the attacker has correctly guessed the first letter of the admin username. Data recovery services reviews They can then move on to letter two and three until they have your admin username. Database 12c new features Once they have that, they can extract your admin hashed password, your admin email, any user email or any data they want, provided they take enough time to run the attack.

Remember, these attacks are automated and incorrect guesses take no time at all, so data can be extracted relatively quickly using this technique. Database lyrics Content based blind SQL injection attacks

A content based blind SQL injection attack is another way for an attacker to extract data from a database when they can’t see the database output.

Lets assume that the value ‘1’ above is an unfiltered query parameter appended to the database query as in our above example. Database 360 Thus an attacker can control all text after ‘ID=’.

1 is obviously not equal to 2 so in the above query the database will return an empty result set. Database architect salary The attacker will examine the resulting page and if it is a page with no content or an error message saying something like ‘no content’, they will know what a response from an empty query with a false condition looks like.

The above query will be empty if the user in the database with ID 1 does not have a username of ‘admin’. Database administrator job description It will however return the a non-empty normal result to the browser if the user with ID 1 does have a username of ‘admin’. Data recovery app Using this technique an attacker can extract data from a database by checking for non-empty and empty responses from the application.

The above query will check if the first letter of the hashed password for user with ID 1 is an ‘a’. R database connection Using this technique, an attacker can go through every character and extract the hashed password for admin accounts. Database weak entity Conclusion

We have explained in detail how SQL injection vulnerabilities and blind SQL injection vulnerabilities work. Data recovery vancouver The key to avoiding these vulnerabilities is to sanitize and escape anything you send to the database. Level 3 data recovery In WordPress the easiest way to do this is by using the prepare() method and using placeholders in your SQL.

Now that you have an understanding of how attackers exploit these vulnerabilities, you will be able to better protect your own websites and those of your customers.

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