I have a pihole set up at home and use tailscale to use it for DNS when I'm out of the house. I noticed more things leaking through recently and narrowed it down to iOS retrying blocked sites over cell data
- Load a known blocked website in Firefox Focus on the phone while monitoring pihole traffic
- Pihole logs the requested site is blocked
- Site loads anyway
- Disable cell data and reload the page
- Page doesn't load
- Re-enable cell data and reload the page
- Page loads
DHCP DNS is being silently ignored and this is an even bigger security issue when using a VPN. Submitted a bug report to Apple through their feedback page
Source: r/ios · by /u/nostradamefrus