How to break AES CBC PADDING with chosen ciphertext attack I'm doing a penetration testing for a web application that uses AES CBC PADDING encryption for the parameter ?email=ciphertext then it's printing the plaintext email on html body.

I would like to know if is there any possibility to : 


Crack the IV or the KEY using chosen plaintext attack?
Can i encrypt a given plaintext?
I believe you can deduce the IV by passing in a chosen ciphertext. This ciphertext should be of the form C = C0||C0, where C0 is the first ciphertext block, and || is the concatenation operator. In other words, send the same block twice!

This will get you two blocks of plaintext, P0||P1. We have that

Decrypt(key, C0) ^ IV = P0
Decrypt(key, C0) ^ C0 = P1


Therefore,

P1 ^ C0 = Decrypt(key, C0)
P0 ^ P1 ^ C0 = IV