Authorization through Vkontakte and security

Question

Facebook

Many websites now make it possible to log in through other popular web services (Vkontakte, Facebook, etc.)

Question: if a person’s Vkontakte account is hijacked, then on those sites where he logged in through Vkontakte, the attacker will be able to do what anything?

Am I speaking correctly?

Answer 1

That is why adequate people do not screw authorization through contact. The muzzlebook has https, at least. And Google will soon tie auth on sms.

Answer 2

Yes

Answer 3

KO warns mankind?

Answer 4

You argue correctly. And in general, there are many, many holes in VK.