Defending Against DNS Hijacking on Public Wi-Fi | Complete Protection with VLESS+Reality
Overview
Public Wi-Fi networks at cafes, hotels, airports, and train stations are convenient but harbor a long-known threat: man-in-the-middle attacks called DNS hijacking. Attackers exploit Wi-Fi router vulnerabilities or set up malicious access points (Evil Twin) to redirect domain names entered by users (such as banking sites) to fake sites, stealing login credentials and credit card numbers. Even in today's HTTPS-everywhere era, the initial DNS response stage remains vulnerable, leaving this risk impossible to ignore.
This article provides a technical explanation of how DNS hijacking works and how Vless's VLESS+XTLS-Reality protocol completely protects user DNS queries from this risk. We cover recommended Hiddify app settings, verification methods, and best practices for deployment to family and team members—offering concrete, immediately actionable content. For remote workers, business travelers, and international tourists, communication safety on public Wi-Fi has become a critical topic for both business continuity and privacy protection.
Why Security Matters Today
Having defenses against DNS hijacking attacks goes beyond mere precaution—it directly prevents real-world damage in the following five concrete scenarios. Attack techniques have grown increasingly sophisticated year by year, and as of 2026, targeted attacks aimed at cryptocurrency and confidential information have also been reported.
- Protection of authentication credentials when accessing banking apps and cloud services (Slack, Notion, etc.) during work at cafes and coworking spaces
- Prevention of credit card information theft when logging into travel services such as Booking.com or Expedia while using hotel Wi-Fi
- Avoidance of corporate information leaks by preventing redirection to phishing sites when checking corporate email at airport lounges
- Mitigation of regional authentication bypass risks when logging into Japanese social media or e-commerce sites from free Wi-Fi abroad
- Complete protection of communication paths to prevent asset theft via fake site redirection when connecting to cryptocurrency exchanges
The VLESS+XTLS-Reality protocol adopts a design principle of "completing DNS queries within the encrypted tunnel," meaning the user's domain queries themselves are invisible to malicious DNS servers or routers on local networks (public Wi-Fi). To maximize this design, Vless adopts a configuration in the Hiddify app's default settings that completely prevents DNS leaks. This means even general users without technical knowledge are protected from DNS hijacking threats simply by turning on the app.
How to Approach It
Step 1: Understanding How DNS Hijacking Attacks Work
A typical DNS hijacking attack flows as follows. Attackers either embed malicious settings in public Wi-Fi routers or set up a fake access point (Evil Twin) nearby. When a user enters "example-bank.com" in their browser, the device sends a DNS query through the router, but the DNS server under the attacker's control returns a fake response (the IP address of a phishing site). The user is led to a visually identical fake site and ends up entering their login credentials. Even with HTTPS, because the initial DNS response is spoofed, the actual communication destination may be the attacker's server even when the URL bar shows the same domain name. VLESS+XTLS-Reality encapsulates the DNS query itself within the encrypted tunnel and performs name resolution via secure DNS servers (Cloudflare's DoH, Quad9's DNS, etc.) on the Vless server side, making local network hijacking fundamentally impossible.
Step 2: Configuring Complete DNS Leak Prevention in the Hiddify App
In the latest version of the Hiddify app (as of May 2026), DNS leak prevention is enabled by default, but here are the verification and optimization steps. Open the app's "Settings" → "Advanced" → "DNS" and confirm that "Force DNS within VPN" is ON. Enable "DoH (DNS over HTTPS) Priority" and select a recommended DoH provider (Cloudflare 1.1.1.1, Quad9 9.9.9.9). Also enable "IPv6 DNS Leak Prevention." This completes a configuration where DNS queries do not leak outside the encrypted tunnel via either IPv4 or IPv6 paths. After configuration, connect your device to public Wi-Fi and visit "dnsleaktest.com" or "ipleak.net" in your browser. Verify that the displayed DNS server is on the VPN provider's side, and that it shows an IP address from the country where the Vless server is located (Japan or the country chosen by the user). If there is no leak, these sites display none of the public Wi-Fi's router information or the original ISP information.
Step 3: Best Practices for Deployment to Family and Team Members
Here are deployment steps to unify security levels across families and small teams. Vless's admin panel offers a sub-account issuance feature for families and teams, allowing you to generate multiple client profiles (QR codes) from your main account. Install the Hiddify app on each family member's smartphone and tablet, then complete setup simply by scanning the QR code. By enabling the app's "Always-On" feature, the VPN automatically activates when members connect to public Wi-Fi—without them having to think about it. There is also the option to VPN-enable the home router itself, in which case all devices (smart TVs, game consoles, IoT devices) are automatically protected. Vless's family plan supports these configurations as standard, creating an environment where even family members without technical knowledge can easily enjoy advanced security.
Summary
Q: With HTTPS (the lock icon), shouldn't I be safe from DNS hijacking?
A: Partially correct, but if the DNS response during initial connection is spoofed, the user may be redirected to a fake site's HTTPS (a site with a valid certificate obtained by the attacker). The lock icon in the URL bar alone cannot distinguish between "the legitimate site's legitimate HTTPS" and "a fake site's legitimate HTTPS." VLESS+XTLS-Reality eliminates this root cause by protecting the DNS query itself.
Q: Are smartphone carrier networks (4G/5G) also at risk of DNS hijacking?
A: Risk is lower than on public Wi-Fi for carrier networks, but scenarios such as international roaming, misconfigured public DNS provided by carriers, or intrusion of malicious intermediate equipment are conceivable. VLESS+XTLS-Reality's DNS protection applies uniformly regardless of network type, so the same level of protection is obtained when using carrier networks.
Q: If asked to set this up for children or elderly family members, are there simple steps?
A: Vless's Hiddify app is designed so that setup is completed simply by scanning a QR code. Share a pre-configured QR code from the main user, and when the recipient opens the Hiddify app on their smartphone and scans it with the camera, the profile is automatically imported and the VPN connection begins. By enabling "Always-On," no conscious on/off operations are required on the recipient's side either.
DNS hijacking attacks on public Wi-Fi remain an effective attack technique even in today's era of widespread encrypted communication, and proper VPN usage is the decisive defense. Vless's VLESS+XTLS-Reality protocol achieves a structure that fundamentally prevents DNS hijacking by encapsulating DNS queries within the encrypted tunnel. With Vless's 2-day free trial, you can verify the DNS leak prevention effect in real public Wi-Fi environments.