this is my first post so I apologise if the formatting of my post isn't perfect.
I should start off by saying that this post is not for any malicious intent, rather for curiosity and understanding AES encryption/decryption.
I have been doing research about AES encryption and everywhere says that ECB mode should never been used and often refers to the famous Linux Tux penguin example. I understand that the vulnerability lies in the fact that a block of plaintext will always produce the same block of cipher text with some key.
However, I am new to this topic and I am struggling to understand the vulnerability in the following situation:
Consider a plaintext (P1) that is encrypted using AES-ECB to produce an encrypted ciphertext C1 with a key unknown to me. If I had another cipher text (C2) that was encrypted using AES-ECB (using the same unknown key), how could I obtain the corresponding plaintext (P2) even if I have P1 and C1 accessible to me?
My confusion lies in the fact that despite having access to P1, C1, and C2 — I do not know the key.