It's possible Apple's Private Relay VPN isn't so private after all

(Image credit: Apple)

A potential security flaw in iCloud Private Relay can lead Apple’s VPN to ignore firewall rules and send some data back to the iPhone maker’s servers.

This leak itself was first discovered by the VPN company Mullvad which was monitoring network connections while working on its own app.

For those unfamiliar, Private Relay functions in a similar way to a VPN tunnel or how Tor works by routing a user’s encrypted network through relay servers before it reaches the internet. The service is currently still in beta and is only available in certain regions though it also requires a paid iCloud+ subscription.

Ignoring firewall rules

According to a new blog post from Mullvad, the VPN company was monitoring network connections when it noticed that QUIC traffic was leaving one of its computers outside of a VPN tunnel.

Disabling Apple’s Private Relay feature made the leaks stop and the company has even provided instructions so that other users can reproduce the leak on their own. Mullvad also pointed out in its blog post that Private Relay (mostly) disables itself as soon as any firewall rule is added to the Packet Filter (PF) system firewall on macOS devices.

> T-Mobile denies blocking iCloud Private Relay, but admits some users won't have access

> What is Apple Private Relay and is it worse than a VPN?

> This Google Chrome challenger could be the best browser for private surfing

As such, the company believes that the leak itself is just some kind of heartbeat signal calling home to Apple. Although it’s impossible to know what information is transmitted to Apple’s servers, the leak does send a clear message to both your local network and ISP that you might be a macOS user.

At this time, Mullvad is unaware of any way to prevent Private Relay from leaking user traffic back to Apple but the company recommends that users disable the feature altogether for the time being if their threat model forbids their local network or ISP from knowing what kinds of devices they’re currently using.

Work securely from anywhere with one of the best business VPNs

Via AppleInsider

TOPICS

After working with the TechRadar Pro team for the last several years, Anthony is now the security and networking editor at Tom’s Guide where he covers everything from data breaches and ransomware gangs to the best way to cover your whole home or business with Wi-Fi. When not writing, you can find him tinkering with PCs and game consoles, managing cables and upgrading his smart home.