Legal liability for assaulting a serviceman

I've just read the news that in Lviv, a man stabbed a TCC serviceman with a knife during a document check, and then used a gas spray and fled. He has already been detained, and criminal proceedings have been initiated for intentional grievous bodily harm and threats (or violence) against a serviceman. What can be the punishment for such actions in general? Can they really impose a very harsh sentence if this happened while the serviceman was performing his official duties?