If you discover a security vulnerability, please report it by opening a private issue or emailing the maintainer directly. Do not open a public issue for security vulnerabilities.

We will acknowledge receipt within 48 hours and provide a timeline for a fix.

• Squid listens on 127.0.0.1 only on the ECS — no public data port exposed
• All proxy traffic encrypted via SSH tunnel
• Access control via SSH key authentication
• SSH host key verified via project-specific known_hosts (StrictHostKeyChecking=yes)
• init displays SHA256 fingerprint for manual verification against ECS console

• deny !Safe_ports — only ports 80, 443, 8443 allowed
• deny CONNECT !SSL_ports — CONNECT only to 443, 8443
• deny to_localhost — blocks 127.0.0.0/8, ::1
• deny to_linklocal — blocks 169.254.0.0/16, fe80::/10
• deny to_rfc1918 — blocks 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, fc00::/7
• deny to_metadata — blocks 169.254.169.254 (AWS), 100.100.100.200 (Alibaba Cloud)
• allow trusted_ip → deny all

• Config file: 0600 permissions
• PAC HTTP server: binds 127.0.0.1 only, random nonce per start
• PAC state file: 0600, atomic write, per-service snapshots
• PID/nonce files: 0600 permissions
• No Basic auth — removed entirely in v0.6.0

• Release archives: SHA-256 checksums verified by installer (fail-closed)
• Checksums signed with cosign (keyless OIDC)
• GitHub Actions pinned to commit SHA
• GoReleaser version pinned to ~> v2

• The PAC nonce prevents port-conflict misidentification, not same-user impersonation
• no_proxy wildcards (10.*) have inconsistent cross-client behavior
• SSH accept-new is no longer used; StrictHostKeyChecking=yes with project known_hosts is enforced