GHSA-q855-8rh5-jfgq: ha-mcp Add-on Settings And Policy Routes Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-q855-8rh5-jfgq",
  "modified" : "2026-07-07T23:41:21Z",
  "published" : "2026-07-07T23:41:21Z",
  "aliases" : [ ],
  "summary" : "ha-mcp: Add-on settings and policy routes are reachable without authentication at the bare root path",
  "details" : "### Summary\n\nIn add-on mode, the ha-mcp settings UI routes are mounted both under the MCP secret path **and** at the bare root of the published port (`:9583`), so Home Assistant ingress can serve the \"Open Web UI\" button. The root-mounted routes perform no authentication — no secret, no `Origin` check, no CSRF token — so any client that can reach `:9583` without the MCP secret can invoke them.\n\n### Affected configurations\n\nHome Assistant **add-on** installations (`host_network: true` with port `9583` published), v7.6.0 and earlier. Docker and standalone installs are **not** affected — there the settings routes are mounted only under the secret path.\n\nRoot-mounted routes in affected versions: tool visibility (`/api/settings/tools` GET/POST), feature flags (`/api/settings/features` GET/POST), the auto-backup suite (`/api/settings/backups…` incl. restore/delete, and `/api/settings/backup-config`), add-on restart (`/api/settings/restart`), and — when the opt-in Tool Security Policies feature is enabled — the approval-policy API (`/api/policy/config` GET/PUT, `/api/policy/approve`, `/api/policy/deny`, …).\n\n### Impact\n\nWithout authentication, a caller that reaches `:9583` — a peer on the local network, a reverse proxy/tunnel that forwards the bare root path (e.g. a whole-host Cloudflared config), or a CSRF `POST` from a page open in a LAN browser — can read or change which MCP tools are exposed, toggle feature flags, list/view/restore/delete backups, restart the add-on, and (with Tool Security Policies enabled) read and rewrite the approval policy, disabling the human-approval gate on gated tools.\n\nThere is **no** access to Home Assistant data, entities, or credentials, and no code execution. All effects are confined to the add-on's own configuration and lifecycle and are recoverable. The primary (same-LAN) vector is within the add-on's documented trusted-network model; remote reachability requires the operator to have reverse-proxied the bare port.\n\n### Proof of concept\n\nWith the add-on running and reachable on `:9583`, from any host that can reach the port without the secret:\n\n```\nGET  /api/settings/tools                 -> 200   (read tool config, no auth)\nPOST /api/settings/tools  {\"states\":{}}  -> 200   (rewrite tool config, no auth / no CSRF token)\nPOST /api/settings/restart               -> 200   (restart the add-on)\n```\n\nThe MCP endpoint itself remains correctly protected by the secret path.\n\n### Patch\n\nFixed in PR homeassistant-ai/ha-mcp#1508 (merged to `master`): the root-mounted add-on routes are restricted to Home Assistant ingress, which always originates from the Supervisor (`172.30.32.2`); every other caller receives `403`. Direct and remote access continue to use the settings UI under the MCP secret path (`…/<secret>/settings`), so the \"Open Web UI\" button, Cloudflared, and the Webhook Proxy add-on are unaffected.\n\nThe fix will ship in the next stable add-on release. If you'd rather have it now, it is already on the dev channel (add-on dev build ` 7.6.0.dev393` or later) — optional; there's no need to switch channels just for this, it is a fairly low risk surface and only exposes the web UI for addon mode only.\n\n### Severity\n\n`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L` = 6.4 (Moderate). Confidentiality impact is None — tool config and backups are not secrets or credentials; integrity and availability impacts are Low — configuration changes and an add-on restart are recoverable.\n\n### Credit\n\nReported by @bharat.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ha-mcp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.10.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/homeassistant-ai/ha-mcp/security/advisories/GHSA-q855-8rh5-jfgq"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/homeassistant-ai/ha-mcp/pull/1508"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/homeassistant-ai/ha-mcp/commit/9f5b085ad4a7b38b067c9da0dc5b45462c4d796e"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/homeassistant-ai/ha-mcp"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-306", "CWE-352" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-07T23:41:21Z",
    "nvd_published_at" : null
  }
}