CVE-2026-32231: ZeptoClaw Generic Webhook Channel Trusts Caller-supplied Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-46q5-g3j9-wx5c",
  "modified" : "2026-03-13T13:35:55Z",
  "published" : "2026-03-12T16:36:48Z",
  "aliases" : [ "CVE-2026-32231" ],
  "summary" : "ZeptoClaw: Generic webhook channel trusts caller-supplied identity fields; allowlist is checked against untrusted payload data",
  "details" : "### Summary\nThe generic webhook channel trusts caller-supplied identity fields (`sender`, `chat_id`) from the request body and applies authorization checks to those untrusted values. Because authentication is optional and defaults to disabled (`auth_token: None`), an attacker who can reach `POST /webhook` can spoof an allowlisted sender and choose arbitrary `chat_id` values, enabling high-risk message spoofing and potential IDOR-style session/chat routing abuse.\n\n### Details\nRelevant code paths:\n\n- `src/channels/webhook.rs:121` sets runtime default `auth_token: None`.\n- `src/config/types.rs:910` also defaults webhook config `auth_token` to `None`.\n- `src/channels/webhook.rs:224` (`validate_auth`) explicitly allows requests when no token is configured.\n- `src/channels/webhook.rs:128` defines `WebhookPayload` with identity fields fully controlled by caller input:\n  - `sender: String`\n  - `chat_id: String`\n- `src/channels/webhook.rs:421` performs allowlist authorization using `payload.sender`.\n- `src/channels/webhook.rs:433` and `src/channels/webhook.rs:434` create `InboundMessage` using untrusted `payload.sender` and `payload.chat_id`.\n\nWhy this is vulnerable:\n\n- The system treats user-provided JSON identity as authoritative identity.\n- Allowlist enforcement does not verify sender authenticity beyond that payload value.\n- `chat_id` is also attacker-controlled, so routing/session association can be steered to arbitrary chats/conversations.\n- If the webhook is exposed without strong upstream authn/authz controls, spoofing is straightforward.\n\n### PoC\n1. Configure the webhook channel in a vulnerable posture (common default behavior):\n   - `enabled = true`\n   - `bind_address = \"0.0.0.0\"` (or any reachable interface)\n   - `port = 9876`\n   - `path = \"/webhook\"`\n   - `auth_token = null` (or omitted)\n   - `allow_from = [\"trusted-user-1\"]`\n   - `deny_by_default = true`\n2. Start ZeptoClaw.\n3. Send a forged request with attacker-chosen `sender` and `chat_id`, without any `Authorization` header:\n\n```bash\ncurl -i -X POST \"http://127.0.0.1:9876/webhook\" \\\n  -H \"Content-Type: application/json\" \\\n  --data '{\n    \"message\":\"FORGED: run privileged workflow\",\n    \"sender\":\"trusted-user-1\",\n    \"chat_id\":\"victim-chat-42\"\n  }'\n```\n\n4. Observe:\n   - Response is `HTTP/1.1 200 OK`.\n   - Message is accepted as if it originated from `trusted-user-1`.\n   - Message is routed under attacker-chosen `chat_id` (`victim-chat-42`).\n\n### Impact\n- Vulnerability type:\n  - Authentication/authorization bypass (identity spoofing)\n  - IDOR-style routing/control issue via attacker-chosen `chat_id`\n- Affected deployments:\n  - Any deployment exposing the generic webhook endpoint without strict upstream authentication and identity binding.\n- Security consequences:\n  - Forged inbound messages from spoofed trusted users.\n  - Bypass of allowlist intent by injecting allowlisted sender IDs in payload.\n  - Cross-chat/session contamination or hijacking by choosing arbitrary `chat_id`.\n  - Potential unauthorized downstream agent/tool actions triggered by malicious input.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "zeptoclaw"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.7.6"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.7.5"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/qhkm/zeptoclaw/security/advisories/GHSA-46q5-g3j9-wx5c"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-32231"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/qhkm/zeptoclaw/pull/324"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/qhkm/zeptoclaw/commit/bf004a20d3687a0c1a9e052ec79536e30d6de134"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/qhkm/zeptoclaw"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/qhkm/zeptoclaw/releases/tag/v0.7.6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-306", "CWE-345" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-12T16:36:48Z",
    "nvd_published_at" : "2026-03-12T19:16:17Z"
  }
}