No, not really. The reason why they want you to keep it as secret is for better management and reducing conflicts/politics among workers.

Imagine, when they newly hire a "10-years-experienced guy" , paying him RM15k.

But in the end, he is totally useless and always "tai chi" every task he gets assigned, while you and the other colleagues are cleaning his ass, but you get only RM8k salary.

This is how politics starts in a company and people will be like "fuck man, why should I do so much while he is getting 2x my salary but doing nothing?"

The business will go down if this situation persists.
But, so far I haven't heard of any punishment for exposing your own salary, especially to non-employee of the same company. Even you have exposed it to your beloved colleagues, you won't get fired due to that reason.

P.S.: I know roughly every of my teammates' salary. I don't ask them on purpose but they sometimes carelessly hinted me about their salary. Like after promotion/increment period, someone said "Hey I just got this certain credit card recently!". Googled, found out that card requires RM6k monthly income to apply.

confidential? lmao, that's what HR wants you to think. they have to protect the rice bowl.

u can't have your own colleague that does same job same scope but gets less than u. then HR will have to handle lots of complain.

so go ahead and post. then the one in the same industry will know if he's under or overpaid. we are here in a forum to help each other out