Yes this can be dangerous, however it depends on many factors from slope, aspect and fuel load. For example if you have a vacant block that is downhill from your house then this is more dangerous than if the block is uphill from your property. You also need to look at the fuel loadings and what types of vegetation is on the block, for example a vacant block with a couple of large trees but otherwise clear poses less threat than a block full of thick scrub that will burn faster…. It’s technical!
If you are concerned then you should discuss this with the land owner, and the RFS can also help.