# Event Loop Blocking + Lazy images {{#include ../../banners/hacktricks-training.md}} In [**this exploit**](https://gist.github.com/aszx87410/155f8110e667bae3d10a36862870ba45), [**@aszx87410**](https://twitter.com/aszx87410) mixes the **lazy image side channel** technique through a HTML injection with kind of **event loop blocking technique** to leak chars. This is a **different exploit for the CTF chall** that was already commented in the following page. take a look for more info about the challenge: {{#ref}} connection-pool-example.md {{#endref}} The idea behind this exploit is: - The posts are loaded alphabetically - An **attacker** can **inject** a **post** starting with **"A"**, then some **HTML tag** (like a big **` ``` {{#include ../../banners/hacktricks-training.md}}