Gain insights into effective security techniques including patching, cryptography, and phishing prevention. Explore practices to make systems resistant and vulnerabilities more detectable, enhancing defense against attacks.

docker.tar.gz

network-commands

node

It seems like hardly a week goes by without a high-profile computer breach. Why do these happen? How can you prevent them? This course doesn’t have all the answers, but it does outline practices that make life harder for attackers and that will help tide you over until you get a full-time security team in place.

In this course, you will learn 5 simple, yet effective, techniques for preventing attackers from getting into your system. These techniques are related to: patching, software vulnerabilities, cryptography, windows security, and phishing. Within each chapter you will learn the best practices for preventing vulnerabilities and how to make them more detectable. 

This course is based on the Pragmatic Programmers’ book, Practical Security, and is aimed at developers, admins, team leads, architects, technology generalists, and all others who stand guard against the things that disrupt the network.

Practical Security: Simple Practices for Defending Your Systems

## Solution: a nested query querying `person`

SELECT CreatedTimestamp, Body
FROM journal_entries
WHERE PersonId =
  (SELECT PersonId
  FROM person
  WHERE FirstName = "Frankie" AND LastName = "Manning");

query_sqli_tables.sql

## Explanation
Let’s take a look at what makes up this SQL statement. We've already seen the first 3 lines in the [Introduction to SQL](https://www.educative.io/courses/practical-security-defending-your-systems/introduction-to-sql/#searching-for-a-specific-persons-entries) lesson. So her, instead of putting in a value for `PersonId`, we retrieve it from the `person` table using a nested query that returns a `PersonId` based on a first and last name. The nested query from lines 4 - 6 is explained here:

- Our statement starts with the SQL keyword `SELECT`. 
- Next, we have `PersonId` which is the column name. This part of the select statement tells the database what data to bring back. 
- After that, we have the `FROM` keyword. This is how we specify which table or tables to query data from, in our case, the `person` table.
- Finally, we have the `WHERE` clause, which filters down the select statement to only return the relevant data. In this case, we have specific `FirstName` and `LastName` columns to match strings against.

---
Now that we have all the prerequisite knowledge, let’s learn how SQL injection works.

# Solution: a nested query querying `person`

# Explanation
Let’s take a look at what makes up this SQL statement. We've already seen the first 3 lines in the [Introduction to SQL](https://www.educative.io/courses/practical-security-defending-your-systems/introduction-to-sql/#searching-for-a-specific-persons-entries) lesson. So her, instead of putting in a value for `PersonId`, we retrieve it from the `person` table using a nested query that returns a `PersonId` based on a first and last name. The nested query from lines 4 - 6 is explained here:

- Our statement starts with the SQL keyword `SELECT`. 
- Next, we have `PersonId` which is the column name. This part of the select statement tells the database what data to bring back. 
- After that, we have the `FROM` keyword. This is how we specify which table or tables to query data from, in our case, the `person` table.
- Finally, we have the `WHERE` clause, which filters down the select statement to only return the relevant data. In this case, we have specific `FirstName` and `LastName` columns to match strings against.

---
Now that we have all the prerequisite knowledge, let’s learn how SQL injection works.

Let's review the solution to the previous challenge.

Introduction

Patching

Vulnerabilities

Cryptography

Windows

Phishing

Solution Review: Write a Generalized Query

Solution: a nested query querying `person`

Explanation

Solution Review: Write a Generalized Query

Solution: a nested query querying person

Explanation

Solution: a nested query querying `person`