Padding Oracle Example

This repository contains a simple example of a padding oracle attack on a vulnerable API.

Code

• vulnerable_api.py : this code simulates a vulnerable API susceptible to the padding oracle attack.
• padding_oracle.py this script performs a Padding Oracle Attack in the vulnerable API.

Attack Scenario

• The attacker has access to a valid payload (IV + encrypted blocks).
• The attacker can use a request function that simulates interaction with a vulnerable API. Specifically, the function returns True if a given payload can be decrypted and False otherwise.
• The encryption algorithm used by the API is vulnerable to a padding oracle attack. In this case, the API uses AES in CBC mode with PKCS7 padding.

Usage

To run the example just cd into the cloned repository and execute

python3 padding_oracle.py

Note

I wrote this code to better understand the algorithm behind padding oracle attacks. It is not optimized, but it is useful for learning. If you want to test a padding oracle attack against an application (with permission, of course), consider using other tools like padre.