If you don’t change the default password on your device, you might as well not have one set. Seriously, it takes seconds to Google sites and manuals, & of course there are other sites that compile lists of these as well.
That’s a recent article about a Russian based website that gloms the feeds from thousands of poorly secured webcams. There are many more.
Also, if you think your router is keeping you safe? Well, if you are letting the devices configure each other to ‘make things easier’ through uPNP, bad luck. uPNP automatically opens ports through your firewall on your router so you can get to the password prompt. (Those ports are also default settings unless you’ve changed them, & that’s often a huge clue as to which default password is required.)
So, get it sorted. Otherwise an enterprising criminal can tune in to your own security cameras to see whether you are worth robbing, in alarming detail.
If you’ve got a web visible CCTV system and it wasn’t professionally installed, then this post should be prompting you to action! If you need advice or help, leave a comment.