Applied Network Security

SQL injection

Now that we have discussed what SQL is and how it works, we will cover some SQL vulnerabilities. As we learned earlier in this chapter, SQL is a set of instructions used to interact with a relational database. Sometimes hackers will manipulate those instructions to exploit how SQL functions. A hacker will manipulate a SQL statement to include a malicious payload within the query of the SQL statement. Here is an example of a normal SQL:

# Define POST variables
uname = request.POST['username']passwd = request.POST['password']# SQL query vulnerable to SQLisql = "SELECT id FROM users WHERE username='" + uname + "' AND password='" + passwd+"'"
# Execute the SQL statement
database.execute(sql)

A hacker would then look at this code ...