Wasn’t the Purpose the Other Way: A Bug in iCloud Private Relay Threatens Users’ Security


Private Relay, introduced by Apple this year, promised users a secure internet experience. Although this feature is not as effective as a VPN in terms of security, the company aimed to save casual users the trouble of trying different VPN applications. However, it was noticed that a flaw in the feature caused a security problem.

tech giant applewhich will allow Safari users to surf the internet more easily, last June. Private Relay announced the (Special Pass) feature. This innovation, which came with iOS 15, offered Apple users a built-in VPN experience, although not entirely. However, it was noticed that the feature that promises a secure internet experience threatens security due to a flaw.

The security threat in question is an encrypted message sent by users. IP addresses by certain means to be revealed it causes. This vulnerability has been fixed in the macOS operating system, but the situation still persists for iOS 15 users.

First things you need to know about the subject:

Apple security

In order to understand the subject, first of all, it allows real-time video and audio conversations on the browser. WebRTC API We need to know things like If you don’t want this, you can skip to the next topic. The WebRTC in question is for connecting two people who will be meeting ICE method uses. This method, without using a proxy server, that is, the information directly transmits it to the other party.


For example, let’s say that Ahmet wants to talk to Mehmet. When Ahmet called Mehmet, ICE elementswell IP address and port information such as goes to Mehmet’s computer. Here you can find all the ICE elements trying When Mehmet’s computer finds the right connection, the two computers have the opportunity to transfer images and audio directly to each other.

Since there are different ICE elements ‘Server Reflexive Candidate‘ is used to avoid confusion. Only the IP address and port information obtained from the STUN server are used here. This information connects Ahmet’s computer to Mehmet’s. NAT and STUN We keep in mind the details of the terms and go directly to the problem.


NAT technology allows many devices over the same IP address allows you to connect to the internet. The smart television, smartphone or computer connected to the modem in your home uses the same IP address in this way. However, in some cases, knowing these addresses and distinguishable must.

At this point STUN Activated. Again, if we go through the example, Mehmet’s IP address and port number are sent back by the STUN server when they connect, and Ahmet’s computer will see this information and see the device of the device to which he will connect. gets your address. We have come to the end of the technical part. Let’s move on to the problem.

Do you need to wait for Apple to fix this?

Private Relay

We said that STUN servers send back public addresses. In Safari, this is iCloud Private Relay. does not pass the filter. We can’t say this is a problem as they don’t provide any other information, but Safari does not reveal the actual IP addresses. Since you export it to JavaScript What falls to malicious people is only your beautiful your real address From other addresses in ICE elements to separate is happening.

This can be easily handled with a little practice. We will not cover how your IP address is revealed by this method, but if you want to reach and take a look at Mostevenko’s detailed article, you can use this link.


Apple Allegedly Ignored 3 Vulnerabilities Found in iOS 15

Users say that there is no need to wait for Apple to solve the problem in question. in the Safari section of the settings WebRTC Sockets Proxying Users who enable the option state that the issue in question has been resolved.

Source : https://appleinsider.com/articles/21/09/25/icloud-private-relay-flaw-leaks-users-ip-addresses

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