Intro

Disable register_globals. display_errors to off - log_errors to on - error_reporting to required level Filter all input

Escaping:

htmlentities($string, ENT_QUOTES, 'UTF-8') to stop code executing mysql_real_escape_string() or addslashes() with mysqli Laravel : no need to clean because it uses PDO

Forms and URLs

XSS = Cross-site scripting CSRF = Cross-site request forgeries.

Tainted data =

• form data
• email
• XML

User can send data as:

• URL param GET
• request param POST
• HTTP header

Semantic URL Attacks

modifying the URL

File Upload Attacks

Danger when displaying. Mime types.

XSS - Cross-site scripting.

Any application which displays input is at risk. Filter input and escape output.

CSRF - Cross-site request forgeries

Using an image is common way to launch Send the victim an image with a URL+params

To mitigate

• use POST not params GET is just for retrieval Make the user use your own forms - add a token .

Spoofed Form Submissions

Spoofed HTTP Requests

Using telnet/PHP/Postman?

Databases and SQL

All data from db must be filtered and all going to must be escaped.

SQL Injection

• failure to filter as it enters app
• and failure to escape data when sent to db

Just use PDO.

Sessions and Cookies

Cookie theft, exposed session data, session fixation and session hijacking.

HTTP is stateless. Cookies invented for this reason.

Cookie theft

This can lead to session hijacking Probably with xss Client side scripts have access to cookies.

Exposed session data

SSL can help

Session Fixation

Session identifier should be kept secret. Make the victim use a session identifier chosen by the attacker.

Page 57?

Look at Laravel stuff now

Now this:

https://www.cloudways.com/blog/prevent-laravel-xss-exploits

Prevent Laravel XSS Exploits Using Validation and User Input Sanitization

Check clean and filter data.

Laravel Sanitization

strip_tags can be added as middleware

Best 2021 Guide To Protect Against PHP SQL Injection Attacks

https://www.cloudways.com/blog/prevent-php-sql-injection/

This is quite good:

https://www.cloudways.com/blog/php-security/

Ultimate PHP Security Best Practices

• Keep PHP updated

Now upload!