GHSA-5fpj-28rv-84r7
Budibase: SSRF in Automation Steps - Webhook, Zapier, N8N, Slack, Discord Bypass IP Blacklist
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @budibase/server | < 3.41.3 | 3.41.3 |
Details
As written in the advisory (Markdown source, shown as plain text).
## Summary
Budibase automation steps (outgoing webhook, Zapier, n8n, Slack, Discord, Make.com) make server-side HTTP requests to user-provided URLs using `node-fetch` directly, completely bypassing the IP blacklist protection that exists in the REST API integration. Additionally, the REST API blacklist itself defaults to empty when `BLACKLIST_IPS` is not configured.
## Vulnerable Code
### Automation Steps (No Blacklist)
All automation steps use `fetch()` directly without any IP validation:
**`packages/server/src/automations/steps/outgoingWebhook.ts` line 69:**
```typescript
const response = await fetch(url, request) // No blacklist check
```
**`packages/server/src/automations/steps/zapier.ts` line 34:**
```typescript
response = await fetch(url, {method: "post", ...}) // No blacklist check
```
**`packages/server/src/automations/steps/n8n.ts` line 53:**
```typescript
response = await fetch(url, request) // No blacklist check
```
**`packages/server/src/automations/steps/slack.ts` line 20:**
```typescript
response = await fetch(url, {method: "post", ...}) // No blacklist check
```
**`packages/server/src/automations/steps/discord.ts` line 29:**
```typescript
response = await fetch(url, {method: "post", ...}) // No blacklist check
```
### REST API Integration (Empty Default Blacklist)
**`packages/server/src/integrations/rest.ts` line 684:**
```typescript
if (await blacklist.isBlacklisted(url)) {
throw new Error("Cannot connect to URL.")
}
```
But `BLACKLIST_IPS` env var defaults to undefined, so the blacklist is empty:
**`packages/backend-core/src/blacklist/blacklist.ts` lines 39-45:**
```typescript
if (blackListArray?.length === 0) {
return false // Always passes when no IPs configured
}
```
## Impact
- **Automation steps**: ANY user can create automations with webhook/Zapier/n8n/Slack/Discord steps pointing to internal IPs. These completely bypass the blacklist module
- **REST API**: Even when BLACKLIST_IPS is configured, it only blocks listed IPs. Default deployments have no protection.
- **Cloud metadata**: `http://169.254.169.254/latest/meta-data/` accessible via any automation step
- **Internal services**: Access databases, admin panels, Kubernetes API on private IPs
## Remediation
1. Apply blacklist checks to ALL outbound HTTP requests, including automation steps
2. Add hardcoded default private IP ranges (127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 169.254.0.0/16)
3. Use a centralized HTTP client wrapper instead of direct `fetch()` calls
4. SSRF protection should be on by default, not opt-in via environment variable
References
External links from the advisory. They lead to third-party sites.