Apple's 'Private Relay' Is Exposing Users' Real IP Addresses

Security researchers found that Apple's iCloud Private Relay can expose users' real IP addresses because some passkey-related requests bypass Safari and its proxy protections at the operating-system level. "In short: any website that supports, or pretends to support, passkeys can see the user's real IP address despite having iCloud Private Relay on," security researcher Tommy Mysk, who discovered the issue along with Talal Haj Bakry, told 404 Media. The flaws also affect OnionBrowser, an iOS app for browsing the web through the Tor anonymity network. It does not, however, impact the official Tor Browser itself. From the report: The researchers developed a site that lets Private Relay users check if the issues impact them. In 404 Media's tests, the site did return the real IP address of a user that was supposed to be protected by Private Relay. [...] In a quirk of how passkeys work -- a broadly secure alternative to usernames and passwords which use the WebAuthn standard -- a user's device makes a web request outside of the browser itself. Meaning, that request essentially bypasses Private Relay and exposes a user's real IP address, even though to them it may look like they are simply interacting with a website as normal. "Because the fetch is issued by the operating system's credential service rather than by Safari, it never enters Private Relay's proxied path. The destination server sees the device's real IP address either way," the researchers write in their research. [...] "We have already informed them. They said the issue was âdire,' but they let us disclose the issue. They didn't provide any time when they will address this," Mysk said.