Flowise: Hardcoded CORS wildcard on TTS endpoint enables cross-origin credential abuse from any webpage — flowise
Permissive Cross-domain Policy with Untrusted DomainsSummary
The TTS generation endpoint sets Access-Control-Allow-Origin: * as a hardcoded response header, independent of the server's CORS configuration. This enables any webpage to make cross-origin requests to generate speech using stored credentials.
Root Cause
// packages/server/src/controllers/text-to-speech/index.ts:83
res.setHeader('Access-Control-Allow-Origin', '*')
res.setHeader('Access-Control-Allow-Headers', 'Cache-Control')
Impact
- Cross-origin credential abuse — any webpage can trigger TTS using stored credentials
- Bypasses the server's CORS policy (
getCorsOptions()) which is otherwise restrictive by default - Combined with Finding 3 (TTS credential abuse), enables drive-by credential abuse via malicious webpages
Suggested Fix
Remove the hardcoded CORS wildcard and let the server's CORS middleware handle the headers:
// Remove these lines:
// res.setHeader('Access-Control-Allow-Origin', '*')
// res.setHeader('Access-Control-Allow-Headers', 'Cache-Control')
References
packages/server/src/controllers/text-to-speech/index.tsline 83
| Software | From | Fixed in |
|---|---|---|
flowise
|
- | 3.1.2 |
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