A brute force attack is a type of cyberattack that attempts to gain access to a system or resource by trying a large number of possible passwords or other combinations. This type of attack is often used against web applications, where attackers try to guess user passwords or API keys.
How Brute Force Attacks Work
Brute force attacks work by trying every possible combination of characters until the correct password or combination is found. This can be a very time-consuming process, but it is often successful if the password is not very strong.
For example, if a password is only 8 characters long and uses only lowercase letters, there are only 26^8 = 208,891,577,600 possible combinations. This means that an attacker could try every possible combination in about 26 days if they were using a single computer. However, if the attacker uses a botnet of 1,000 computers, they could try every possible combination in just over 2 hours.
Types of Brute Force Attacks
There are two main types of brute force attacks:
Dictionary attacks: These attacks use a list of common passwords or words to try to guess the correct password. This is the most common type of brute force attack, and it is often successful because many people use common passwords.
Rainbow table attacks: These attacks use a pre-computed table of password hashes to quickly find the correct password. A password hash is a unique value that is generated from a password. It is very difficult to reverse a password hash, but it is relatively easy to store a large number of password hashes in a table. This table can then be used to quickly find the correct password if the attacker knows the hash value.
How to Prevent Brute Force Attacks
There are a number of things that can be done to prevent brute force attacks, including:
Using strong passwords: Passwords should be at least 12 characters long and should include a mix of upper and lowercase letters, numbers, and symbols.
Enforcing password complexity rules: Password policies should be enforced to ensure that passwords are strong and complex.
Using CAPTCHAs: CAPTCHAs can help to prevent automated brute force attacks. CAPTCHAs are challenges that are designed to be easy for humans to solve but difficult for computers to solve.
Limiting login attempts: Login attempts should be limited to a certain number per IP address or time period. This will help to prevent attackers from flooding the server with login attempts.
Using two-factor authentication: Two-factor authentication adds an extra layer of security by requiring users to enter a code from their phone in addition to their password.
Additional Tips
Use a password manager to generate and store strong passwords for all of your online accounts.
Keep your software up to date. Software updates often include security patches that can help to protect your system from brute force attacks.
Be careful about what information you share online. If an attacker knows your name, birthday, or other personal information, they may be able to guess your password.
Conclusion
Brute force attacks are a serious threat to web applications, but they can be prevented by following the tips above. By taking the necessary precautions, you can help to protect your accounts and your data from these attacks.
Additional Resources
OWASP Brute Force Attacks: https://owasp.org/www-community/controls/Blocking_Brute_Force_Attacks
Imperva Brute Force Attack Prevention: https://www.imperva.com/learn/application-security/brute-force-attack/
Sucuri Guide to Brute Force Attacks: https://sucuri.net/guides/what-is-brute-force-attack/
