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Docker Desktop MacOS Ignores Host_binding_ipv4, Exposing Supabase Local Dev Ports To LAN

The documented Docker network host binding to 127.0.0.1 does not restrict access on macOS because Docker Desktop runs Docker inside a Linux VM, causing local Supabase services to remain reachable from other devices on the same LAN.

highConfidence 88%Docker Desktop

Origin Analysis

Docker Desktop on macOS runs the Docker daemon inside a Linux VM. The Docker network option com.docker.network.bridge.host_binding_ipv4=127.0.0.1 only affects binding inside that VM, while Docker Desktop's userland proxy forwards published ports to all host interfaces, ignoring the bridge IP binding on the macOS host.

1. On macOS, install Docker Desktop. 2. Run: docker network create -o 'com.docker.network.bridge.host_binding_ipv4=127.0.0.1' local-network 3. Start Supabase: npx supabase start --network-id local-network 4. Find the Mac's LAN IP using ifconfig. 5. From another device on the same network, open http://<LAN-IP>:54323 in a browser. 6. Supabase Studio loads despite the documentation stating only localhost access is allowed.

Fixing Code Block

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0x48 8D 3D 22 01 00 00 E80x91 FF 0A 63 2E 57 B8 04
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0xFF 15 40 20 60 00 48 890xC3 90 7A 01 4C 28 B1 56
0x0F 1F 44 00 00 55 48 890xE5 C3 18 6D 92 0B 33 A7

Edge Case Audit

The script replaces the entire active pf ruleset, which may disrupt existing firewall or VPN policies. Always back up current rules (the script does this to /tmp/pf-backup-*). The rules are not persistent across macOS reboots and must be reapplied manually or via launchd. If you need to use other services on the listed ports from external interfaces, adjust or remove those ports. Rollback: restore the backup with sudo pfctl -f /tmp/pf-backup-<timestamp>.rules or disable pf with sudo pfctl -d.