DNS Leak in Brave When Using Proxy SwitchyOmega 3 (ZeroOmega) — No Leak in Google Chrome

Brave Browser Desktop Support
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Summary

When using Proxy SwitchyOmega 3 (ZeroOmega) with a Switch Profile (proxy selection based on hostname), Brave leaks DNS requests to the system/ISP DNS.

The same extension and configuration works correctly in Google Chrome with no DNS leak.

Environment

  • Extension: * Proxy SwitchyOmega 3 (ZeroOmega)

    • Users: 600,000+

  • Brave Version:

    Brave 1.85.118 (Official Build) (arm64)

    Chromium: 143.0.7499.169

  • Chrome Version: 143.0.7499.170 (Official Build) (arm64)

  • OS: macOs 15.7.3 m3

Steps to Reproduce

  1. Install Proxy SwitchyOmega 3 (ZeroOmega) in Brave

  2. Create a proxy profile (SOCKS5)

  3. Create/Use the Auto Switch Profile that routes traffic based on hostname rules and make the proxy profile defualt.

  4. Enable the Auto Switch Profile

  5. Visit a DNS leak test site

  6. Observe DNS resolving via system/ISP DNS

  7. Repeat the same steps in Google Chrome

  8. Observe DNS resolving through the proxy (no leak)

Expected Result

DNS requests should be routed through the proxy when a Switch Profile is active.

Actual Result

DNS requests bypass the proxy and leak to system/ISP DNS when using a Switch Profile in Brave.

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