I posted this on the official PoE/Obsidian forums, I wanted to re-post it here.

Hello, I'll begin by saying this bug/glitch is rather balance breaking for Hiravias/druids. Whenever I rest Hiravias at a tavern/campfire the base intelligence goes up by 2. And yes, this also includes the rest bonuses gained from resting at a tavern if I pick a +intelligence. On my current save, I have logged 35 hours, I only picked up Hiravias 13 playtime hours ago. The base starting int was 11. At the moment with 29 int (including item bonuses) the AoE effect range is 114% 95% duration and +34 to will. I find this glitch to be very funny too, considering that druid's in my opinion are a under performing class. Hiravias with this unbalanced issue can easily hold down entire mob groups. Please notify me if anyone desires a save file, I'll upload it. I'm curious if anyone else has had this occur to them.

*Hiravias only has one +2 int item on the character, it's the "Drinking horn of moderation" which gives a +2 int bonus when health is above 50% and x1 focus gain. The item properity is "unconquerable"

Quick note, I opened up the save file and removed then rested with the "Drinking Horn of Moderation" off the character. The base int did not increase, so this is a item bug. It'll increase your character's int by +2 each time you rest. Quite the little exploit if you want to increase caster AoE range.