How Can VPN DNS Leak Be Vulnerable?
DNS leak is a privacy threat mainly because it vanishes the cause of using a VPN tool and exposes your identity. With such anonymity loss, the snoopers are actually able to monitor all your internet traffic including the websites you visit, the files you download, the services you are using and many other things as well.
DNS leaks are more alarming than the regular snooping because most of the people or organizations which are using identity obscuring tools are carrying out the activities keeping their online presence safe in mind. That’s why many hackers tend to intercept VPN user privacy through certain efficient techniques.
DNS leak is one of the malignant techniques that are used by data hackers and cyber goons to extract your data invisible. For instance, a hacker could regulate a website or alter it to make it slow. When the website is working slow or is extremely lagging while loading then the website accesses the older DNS server which is ISP DNS. This makes the user information visible and easy to gather.
Another method to prompt DNS leak is when an individual connects to public Wi-Fi. Despite the fact that tools like VPN or Tor make public Wi-Fi safe, the chances of DNS leak are still there. The attacker could alter your device settings in order to regulate your DNS traffic outside the VPN tunnel.
What Is DNS Leak?
In regular situations, your browser is sending DNS requests to ISP DNS server which is a default set up in most of the devices. When you enter a URL, the browser sends a request to the ISP notifying that the user wants to access a particular site (the URL you entered). Through this procedure, the ISP is aware of all the browsing activities of a user.
Therefore, to hide the browsing history from ISP, most individuals use anonymous DNS servers such as the VPN server. While being connected to a VPN, the DNS requests should formally be transmitted to the VPN DNS servers, however; sometimes the DNS requests leak to the ISP servers and all the browsing activities are exposed.
The cause of such DNS leak is the default in your VPN and when the VPN is not monitoring the DNS requests. For instance, a VPN might ignore the requests or may use the default settings of the device due to which the DNS requests are exposed to the ISP. The cause of DNS leak is not only due to the fault of your VPN provider, it might be due to the device alteration.
The system reboot, upgrade or clean install is a probable cause of default DNS setting. Yet, some of the browser vulnerabilities such as WebRTC may expose IP address and DNS to the internet provider for which there are different prevention.
On the other hand, the Windows device especially Windows 10 has increased chances of DNS leak. This is because the latest Microsoft operating system tries to make your browsing as fast as possible and therefore, it sends numerous DNS requests through VPN servers from which some might leak to the ISP DNS as well.
The problem is not always regarding your VPN provider however, an updated and efficient VPN could evade the DNS leak issue with continuous monitoring of transmitting DNS requests.
What Is DNS And How It Works?
There is a Domain Name System or simply DNS so that your device could better communicate with the internet system. Without DNS, the internet isn’t able to operate and show you the desired browsing result.
All the devices have an IP address through which the computer or devices work together and identify each other. This IP also helps the internet or your browser to identify the device to which the results should be sent. The browser is incapable of understanding the words and a human being isn’t so good at memorizing numbers.
For instance, an individual could easily remember a URL in a word form such as www.example.com instead of 123.123.123. Therefore, a DNS system is developed that switches the URL into the IP form.
Here is a simple explanation that why a DNS is important and how it operates to determine the meaning of a query entered on the internet. For instance, you entered a URL www.vpninsights.com into your browser. The browser will then send the request to your DNS server which rapidly transforms it to the IP address which is set up for that domain name. With that IP address, your browser displays you the website information and all this process completes in seconds.
How To Test Your DNS Leak
It is important to regularly check your VPN performance through DNS leak test. It is the most convenient way of confirming the vulnerability so that it could be fixed.
The VPNInsight’s DNS test tool lets you check the efficiency of your VPN. The process of checking DNS leak is really simple and quick process. You have to follow these easy steps;
- Step 1: Connect your VPN and click the button “Execute Test”.
- Step 2: The site will display DNS results.
From these displayed results you could easily figure out the DNS leaks. If the list contains your real ISP hostname, real IP address or country then the VPN is leaking your DNS requests.
DNS leak is a serious privacy threat because you are kept under the secure feeling, alongside; the anonymity network might be leaking your private data.
How Your IP Could Be Leaked
Many internet users frequently ask, “What causes DNS Leak?” the answer to this question is “Many reasons”, with some of them being Torrent DNS IP Leak, WebRTC DNS Leak, and VPN IP DNS Leak.
Torrent DNS IP Leak
When you're torrenting, DNS leak assurance is just imperative on the off chance that you need to conceal your connection amongst you and the trackers and UDT from your ISP. Your torrent client can inject your IP address into every packet it sends to the tracker. In this way, torrenting can reveal your DNS with this process being called “Torrent DNS IP Leak”.
WebRTC DNS Leak
WebRTC, short for Web Real-Time Communication is a standard accessed by web browsers like Chrome, Firefox, and Opera to permit the utilization of voice calling or a video visit specifically from a browser. What it likewise does is it perceives the client's actual IP address regardless of which VPN they utilize. There is no chance to get of shielding yourself from WebRTC causing a DNS leak. This vulnerability is named as WebRTC DNS leak.
VPN IP DNS Leak
With a VPN, all activity for anonymous networks is directed through a VPN. So your real association is secured. Despite, your DNS asks for are not bound to an unknown network: it is directed to the local network, which is known to your PC. It is sent straightforwardly to the nearby DNS server without experiencing VPN. The nearby DNS server recognizes what DNS queries you made and that it was you who made them. This is called VPN IP DNS leak.
IPv6 DNS Leak
As we have discussed in detail that the DNS leak occurs while a person is connected to the VPN. Along with other causes, IPv6 is also a major factor in this issue.
IPv6 is the latter version of IPv4 that was introduced mainly because of the shortage of unique IP address. Yet, you can see the more detail about the differences between IPv4 and IPv6 to get a better idea.
Like many websites, many VPN providers also have a single support and that’s for IPv4. Therefore, their DNS could only deal with the requests of websites which are using IPv4 protocol. So, when a website sends IPv6 address request, the VPN DNS is unable to answer and eventually, the ISP server is accessed. This is known as IPv6 DNS leak and in this circumstance, your sensitive data is exposed.
Fortunately, there are VPN providers which now have a feature of IPv6 leak protection which is specially designed to mitigate this risk.
Here Are the Major DNS Leak Issues
Irregular Network Configuration
Most of the people switch their Wi-Fi connection between the various networks such as the office Wi-Fi, home network, or any public internet connection. This creates an unstable DNS system and could generate the threat of DNS leak.
When you are connecting to the VPN, it is necessary that your device connects to the local network first. There should be proper settings to prevent data leaks as the DHCP settings can automatically assign a DNS server when you connect to a new network and this could probably be the ISP DNS server. In case you connect VPN on this network afterwards then also the DNS request could ignore VPN encrypted tunnel and cause DNS leak.
The IPv6 version of IP addresses is a successor of IPv4 which was introduced due to the shortage of IP addresses. The increased number of internet connected devices has raised the need of unused IP addresses which are really low in IPv4. Therefore, the IPv4 is being replaced by the IPv6, yet the number of IPv6 implemented protocol is still really low.
Due to this transition phase between IPv4 and IPv6 protocol, the DNS leak issue has been increased. Most of the VPNs have IPv4 support and any of the request to or from a IPv6 device could not be resolved by such VPNs. Also, the request sent from machine using dual-stack tunnel which converts IPv4 to IPv6 couldn’t be handled by these VPNs. Therefore, the DNS request eventually goes to the ISP DNS server and your DNS leak causes real IP to expose.
Windows OS Versions (8, 8.1 or 10)
The latest versions of Windows have some features that are purposed to enhance user experience but they have prominent effects on DNS leak issue. For instance, the feature of Smart Multi-Homed Named Resolution has been introduced in Windows 8 and later versions. This is to enhance internet browsing speed and tends to send a request to all available DNS servers.
This feature makes sure that response from the non-standard DNS server is only accepted if the favorites fail to respond. Therefore, it is most probable that ISP DNS response is accepted which eventually results in DNS leak.
In Windows 10, the feature works in a way that it accepts the DNS response from the server which response the fastest. This cause DNS leak as well as open the chances of intended DNS leak or DNS spoofing as discussed above.
Transparent DNS Proxies
Many ISPs enforce their own DNS servers if they detect a user changing his DNS server setting to a third party server. The transparent server will interrupt the user web traffic and send it to the ISP DNS server. This has the main purpose that the internet provider gets DNS request through DNS leak. Fortunately, such types of servers are detected through DNS leak test.
Microsoft has introduced the Teredo technology to resolve the issue of IPv6 and IPv4. This feature is build-in in the Windows operating system and changes the IPv6 address to IPv4 in order to make sending, receiving, and understanding IPv6 possible on IPv4 connection.
However, for VPN connection it could result in DNS leak as it is a tunneling protocol and it could bypass the VPN’s encrypted tunnel too.
How To Prevent DNS Leak
DNS leak could be avoided through setting changes to your devices, operating systems, and browsers. It is most probable that your DNS requests are set up to ISP DNS server, so change it to a more secure DNS server. However, there are some other DNS issues too which could be resolved through various DNS leak fixes. You can see these fixes here.
DNS leaks are a major concern as they threaten privacy even in the presence of privacy tools such as VPN. This is more concerning because a user is thinking that all his activities are going through an encrypted channel, however, ISP is looking on every act.
Therefore, it is necessary to prevent DNS leak through intelligent VPN selection and other setting changes. Above all, you should regularly run DNS leak test to avoid any threat and unwanted situation.