{
  "parent_root_cause": "AutoBangumi seeds a hard-coded default administrator account (admin/adminadmin) via UserDatabase.add_default_user() whenever the users table is empty (called from startup start_up()/first_run()), and POST /api/v1/auth/login accepts those publicly known credentials and issues an admin JWT, granting full admin API access on a fresh instance.",
  "parent_sink": "POST /api/v1/auth/login -> UserDatabase.auth_user -> verify_password(adminadmin) -> _issue_token (admin JWT, sub=admin) -> token cookie accepted by get_current_user for all protected endpoints.",
  "variant_1_root_cause_equivalence": {
    "equivalent": true,
    "confidence": 0.95,
    "rationale": "Variant 1 is the identical root cause and identical sink exercised on the FIXED/LATEST version. add_default_user() (backend/src/module/database/user.py) seeds admin/adminadmin unchanged from 3.2.6 through 3.3.0-beta.2 (only an async DB refactor in 3.3.0-beta.2). The login handler (backend/src/module/api/auth.py) is unchanged in substance (no setup gate added). The referenced fix (487bdfec) does not touch either file. Therefore the parent root cause is reachable on the patched version with the same entry point and the same sink — a true bypass."
  },
  "variant_2_root_cause_equivalence": {
    "equivalent": true,
    "confidence": 0.8,
    "rationale": "Variant 2 reaches the SAME impact (fresh-instance admin takeover via the auto-seeded admin account) through a DIFFERENT entry point (POST /api/v1/setup/complete instead of /auth/login) and a different sink (db.user.update_user('admin', UserUpdate(username,password)) commits a password reset, then /auth/login with the attacker's creds). It is tightly coupled to the CVE root cause: it depends on the auto-seeded 'admin' row existing (created by add_default_user()) and on the absence of a setup-completion gate on /auth/login. It is arguably a distinct CWE-306 first-run-takeover, but it shares the same 'fresh instance auto-seeds a known admin account with no auth gate' underlying condition, and any fix to the default-credentials CVE must cover it. Classified as same-root-cause-equivalent (alternate trigger) rather than a fully separate unrelated bug."
  },
  "ruled_out_separate_bugs": [
    {
      "candidate": "DEV_AUTH_BYPASS (get_current_user returns 'dev_user' when module.__version__ unimportable)",
      "same_root_cause": false,
      "rationale": "Distinct root cause (missing version file -> auth disabled), not default credentials. Ruled out for official images (real VERSION shipped; no-auth /api/v1/rss -> 401). Not claimed as a variant."
    },
    {
      "candidate": "Bearer login_tokens bypass (settings.security.login_tokens)",
      "same_root_cause": false,
      "rationale": "Admin-configured API tokens, not derived from default credentials; login_tokens defaults to empty. Not a default-credentials variant."
    },
    {
      "candidate": "Passkey/WebAuthn login (/api/v1/passkey/auth/verify)",
      "same_root_cause": false,
      "rationale": "Requires a registered WebAuthn credential; cannot be triggered with default credentials on a fresh instance. Not a default-credentials variant."
    }
  ],
  "trust_boundary": "Both confirmed variants cross the network trust boundary: unauthenticated remote HTTP (port 7892) on a fresh, deployed AutoBangumi instance -> admin API. This is remote unauthenticated takeover, not user-self-attack on a local file.",
  "target_security_policy_scope": "SECURITY.md defines supported versions and a reporting process only; it does not exclude default credentials, first-run setup, or pre-auth setup endpoints from scope. The variant findings are within the target's stated security scope.",
  "conclusion": "same_root_cause_confirmed_with_one_bypass_and_one_alternate_trigger"
}