Anyone know exactly what they could see if you’re on a personal device but work-wifi?
Usually the websites and apps you use, but not what specific page you visit and it’s content.
If you for example visit https://en.wikipedia.org/wiki/Labor_unions_in_the_United_States they could see that you visited https://en.wikipedia.org/ but nothing more.
This is assuming that the website is encrypted (it starts with https://, not http://), which nowadays luckily most websites are. Otherwise they can see the specific page, it’s content and most likely also all information you input on that page.
if the company had installed something that uses similar technology as a pihole, wouldn’t they technically be able to see everything even if you use https?
Mostly no. PiHole works by providing a DNS server.
A DNS server is responsible for turning domain names such as en.wikipedia.org into internet protocol addresses such as 185.15.58.224.
PiHole has a list of known ad serving domains and when asked to resolve one just replies with an invalid address.
Running the DNS server itself would only give them access to the above mentioned data. However, they could respond with wrong addresses to redirect all traffic over a man in the middle proxy.
For an https secured connection this would just result in a certificate error, warning the user to not proceed. Https secured websites have a certificate electronically signed by a trusted outside party, that verifies that they really are the owner of a specific domain.
Another option would be to redirect the user to a man in the middle proxy that pretends to not support https in order to trick the browser and server into opening an unencrypted connection. This works on some websites, but can be noticed by the user (as the browser now displays “Not Secure” and “http://”) in the address bar) and is protected again by newer security mechanisms like HSTS that allow websites to tell browsers to always contact them over https in the future.
Basically if the site supports HSTS and you have visited it before this also won’t work.
