Vulnerabilities in pkg:npm/@kozou/core

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-v52w-28xh-v562",
  "modified" : "2026-06-19T20:47:19Z",
  "published" : "2026-06-19T20:47:19Z",
  "aliases" : [ ],
  "summary" : "Kozou: Unauthenticated MCP HTTP server and bundled dev-stack hardening (DNS-rebinding, request-body limits, read-only reads, default network exposure)",
  "details" : "Kozou compiles a PostgreSQL schema into an Admin UI, a REST API, and an MCP server. Several hardening gaps in the bundled HTTP surfaces and the scaffolded dev stack are fixed in **1.8.1**.\n\n## Issues\n\n1. **MCP HTTP server lacked DNS-rebinding protection.** The Streamable HTTP transport is unauthenticated and loopback by default. Without `Host`/`Origin` validation, a malicious web page in the operator's browser could rebind a hostname it controls to the loopback address and drive the MCP endpoint — reading schema metadata, or (when the opt-in `call` execution tool is enabled) executing exposed functions as the execution role.\n\n2. **Unbounded request-body buffering (DoS).** Both the MCP HTTP server and the in-house REST server read the entire request body into memory with no size limit, so a reachable client could drive the process toward memory exhaustion.\n\n3. **Read requests ran in a read/write transaction.** The shared role-transaction envelope opened every request with a plain `BEGIN`, so a `GET` ran read/write. A `SELECT` that reaches a volatile function or a writable / `INSTEAD`-triggered view could perform a write that then commits — the \"a GET only reads\" contract was left to the serving role's grants rather than enforced.\n\n4. **No-auth dev surfaces published on all interfaces by default.** The scaffolded `docker-compose.yml` (and the quickstart) published the unauthenticated Admin UI and MCP HTTP server — and the default-credential demo database — on every host interface, and the config defaulted those binds to `0.0.0.0`.\n\n## What changed in 1.8.1\n\n- **DNS-rebinding guard (MCP HTTP):** the server validates the `Host` header (and a present `Origin`) against an allowlist before handling any request, on every route. Matching is on the hostname; loopback names are always accepted and an operator can add hosts via configuration. A browser cannot forge `Host`/`Origin`, so this closes the rebinding vector. (This is a browser-rebinding defence; network reachability of an unauthenticated server must still be constrained by the network — see workarounds.)\n- **Request-body size cap:** both HTTP servers reject an over-large declared `Content-Length` (413) and enforce the limit while streaming, so a chunked / `Content-Length`-less body cannot grow unbounded. A non-JSON `Content-Type` on a body is rejected with 415. The cap is configurable.\n- **Read-only read transactions:** read methods (`GET`) now run in a `READ ONLY` transaction, so the database refuses any write for the duration of the request regardless of the role's grants.\n- **Loopback-by-default network posture:** the Admin UI and MCP HTTP server now bind loopback by default; the bundled compose files publish every host port (Admin UI, MCP, database) on `127.0.0.1` only, while the container binds all interfaces internally so the loopback mapping still works. Operators opt into a broader bind explicitly.\n\n## Impact\n\nThe MCP HTTP server's exposure is greatest when the opt-in `call` execution tool is enabled and/or the server is reachable beyond loopback. The read/write-transaction issue has effect only when the schema exposes a read path that can write (a volatile-function-backed column or a writable/`INSTEAD`-triggered view) and the serving role holds write grants. The all-interface publish affected anyone who ran the scaffolded `docker compose up` on a host reachable from an untrusted network. Requests run under `SET LOCAL ROLE`, so PostgreSQL still enforces grants/RLS at runtime; these are defense-in-depth and read-contract hardening.\n\n## Affected / patched\n\n- npm packages `kozou`, `@kozou/api`, `@kozou/mcp`, `@kozou/core` (and the lockstep-versioned siblings): affected `<= 1.8.0`, patched **1.8.1**.\n- Container image `ghcr.io/kozou-dev/kozou`: patched at tag `v1.8.1`.\n\n## Workarounds (if you cannot upgrade immediately)\n\n- Bind the Admin UI and MCP HTTP server to loopback and publish their host ports on `127.0.0.1` only; do not expose them to untrusted networks.\n- Do not enable the MCP `call` execution tool on a non-loopback / unauthenticated deployment.\n- Put an authenticating reverse proxy (with `Host`/`Origin` validation and a request-body limit) in front of any non-loopback deployment.\n- Change the demo database's default credentials and restrict its port.\n\n## Patches\n\nUpgrade to **Kozou 1.8.1** (all npm packages and the `ghcr.io/kozou-dev/kozou` image).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "kozou"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.8.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.8.0"
    }
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@kozou/api"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.8.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.8.0"
    }
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@kozou/mcp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.8.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.8.0"
    }
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@kozou/core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.8.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.8.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/kozou-dev/kozou/security/advisories/GHSA-v52w-28xh-v562"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kozou-dev/kozou"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1188", "CWE-272", "CWE-346", "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T20:47:19Z",
    "nvd_published_at" : null
  }
}