What to do with a colleague who got a promotion that he does not deserve?

I have been working in Dubai with a company for 2 years now. Last year, I was “verbally” promised of promotion but due to Covid19, things changed. Two months ago, we went for an interview to decide who will be selected.

We are six; including a guy who since joining the company was transferred to 4 different locations because of sexual harassment without taking any action against him because his cousin works as a financial manager in the head office.

Everyone was surprised when he was selected despite everything, our direct manager told me that they were going to terminate him but things changed.

I want to know if there is anything that can be done. I have witnesses to his previous behavior and reports; the majority of the team knows about him but afraid to come forward because they might lose their jobs, so what can we do?

Thank you for your help!

I need advice on whether to go after this or forgot it.