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80 lines
3.8 KiB
Markdown
80 lines
3.8 KiB
Markdown
# Security guidance
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This project can perform security-sensitive operations (bans, configuration changes). Deploy it as you would deploy every other administrative interface.
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## Recommended deployment posture
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- Do not expose the UI directly to the Internet.
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- Prefer one of:
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- VPN-only access
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- Reverse proxy with strict allowlists
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- OIDC enabled (in addition to network controls)
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If you must publish it, put it behind TLS and an authentication layer, and restrict source IPs.
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## Input validation
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All user-supplied IP addresses are validated using Go's `net.ParseIP` and `net.ParseCIDR` before they are passed to any integration, command, or database query. This applies to:
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- Ban/Unban callbacks (`/api/ban`, `/api/unban`)
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- Manual ban/unban actions from the dashboard
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- Advanced action test endpoint (`/api/advanced-actions/test`)
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- All integration connectors (MikroTik, pfSense, OPNsense)
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Integration-specific identifiers (address list names, alias names) are validated against a strict alphanumeric pattern (`[a-zA-Z0-9._-]`) to prevent injection in both SSH commands and API payloads.
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## WebSocket security
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The WebSocket endpoint (`/api/ws`) is protected by:
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- **Origin validation**: The upgrade handshake verifies that the `Origin` header matches the request's `Host` header (same-origin policy). Cross-origin WebSocket connections are rejected. This prevents cross-site WebSocket hijacking attacks.
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- **Authentication**: When OIDC is enabled, the WebSocket endpoint requires a valid session.
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## Callback endpoint protection
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The fail2ban callback endpoints (`/api/ban`, `/api/unban`) are only reachable with a correct `CALLBACK_SECRET`. This secret must be atleast 20 characters long. If not specified a secure secret, will be automatically genereated on first start. It can be further protected by:
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- Use even a stronger `CALLBACK_SECRET` than our default (32 characters)
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- Make network restrictions (only allow known Fail2Ban hosts to reach the callback endpoint)
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Rotate the secret if you suspect leakage.
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## SSH connector hardening
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For SSH-managed hosts:
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- Use a dedicated service account (not a human user).
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- Require key-based auth.
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- Restrict sudo to the minimum set of commands required to operate Fail2Ban (typically `fail2ban-client` and optionally `systemctl restart fail2ban`).
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- Use filesystem ACLs for `/etc/fail2ban` rather than broad permissions to allow full modification capabilities for the specific user.
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## Integration connector hardening
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When using external firewall integrations (MikroTik, pfSense, OPNsense):
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- Use a dedicated service account on the firewall device with the minimum permissions needed (address-list management only on MikroTik; alias management only on pfSense/OPNsense).
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- For pfSense/OPNsense: use a dedicated API token with limited scope.
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- Restrict network access so the Fail2ban-UI host is the only source allowed to reach the firewall management interface.
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## Least privilege and file access
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Local connector deployments typically require access to:
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- `/var/run/fail2ban/fail2ban.sock`
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- `/etc/fail2ban/`
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- selected log paths (read-only, mounted to same place inside the container, where they are on the host.)
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Avoid running with more privileges than necessary. If you run in a container, use the repository deployment guide and SELinux policies.
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## SELinux
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If SELinux is enabled, use the policies provided in (according to your specific setup they are not enough):
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- `deployment/container/SELinux/`
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Do not disable SELinux as a shortcut. Fix always labeling and policy issues instead. -> Everytime you read "to disable SELinux" you can close that guide :)
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## Audit and operational practices
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- Back up `/config` (DB + settings) regularly.
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- Treat the database as sensitive operational data.
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- Keep the host and container runtime patched.
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- Review Fail2Ban actions deployed to managed hosts as part of change control. |