Players in Visitor mode can interact with the ender dragon egg

Steps to Reproduce:

1. Place a dragon egg
2. Set your permission level to Visitor
3. Right-click on the dragon egg

Observed Results:
The dragon egg teleports.

Expected Results:
The dragon egg should not teleport.

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Original Description:
(Note: I am typing this on my phone, so sorry if text is a bit wonky) Pretty much, I have a survival world with the default permissions on visitor, so if random friends of my friends that log on cannot affect or grief anything. I'm playing with one of my friends, and a random dude he played and friended with once joins my world. He then walks into my house, as the door is open, climbs upstairs to the egg, and hits it, and it teleports. I then logged off immediately so that he wouldn't teleport it anymore, and it would have the world for him cut off, and then I blocked him. How could he have hit the egg, when he was on visitor the whole time? I think it's a bug. Anyway, please fix this!