At the beginning I'd like to inform that the case refers to US law, which I am completely unfamiliar with.
Cutting to the chase, I've been recently training reverse engineering skills on lately published, closed-source application. I found that there is a serious vulnerability which allows to easily bypass serial code verification.
And now I want to report this to authors, so that they can fix it. Of course the research I've made on this application was solely in order to broaden my knowledge on reverse engineering and I was not going(and I am still not) to publish any kind of crack. I am acting in good faith intention.
So I want to know whether the authors could accuse me of breaking copyrights, etc. if they turned out to be unfriendly?