Thanks for the Wiki link. I was going to suggest طريق حديدي but this feels like something rough, while the idea of a via ferrata is to render climbing easier.
I noticed 2 things from the wiki page:
1- the term is used as is in most languages (i.e. not translated)
2- there are via ferrats in Oman:
There are 5(five) routes in Oman; 3 are operated by the Ministry of Tourism; Jabal Shams, Wadi Bani Awf (Snake Gorge) and Bandar Khayran (Western Isle) which have been out of commission since 2012. Currently only two are operating; which are privately run by Alila Jabal Akhdar – one is level 2 and the second is level 5, that includes a suspended bridge walk (22 metres) across a cave mouth
So, I suggest you either keep the Italian words as they are and just transliterate them in Arabic letters, or you do some research about those Omani roads and see how they're referred to in Arabic there.