RSA is the most common category in CTFs, this is due to the simplicity of RSA and the existance of a couple of attacks that depend on the context of implementation and parameters, cracking a secure and well implemented RSA should be as hard as factoring the moduli $N$.

src: @its_v0lt in cryptohack discord

I'll try in this blogs to explain some common attacks on RSA, let's begin with wiener's attack [TODO: wiener's attack, coppersmith, LLL stuff, boneh durfee, pollard rho and stuff in AItMC, do some examples for SECCON / actual ctfs]