GHSA-5FW2-MWHH-9947

Vulnerability from github – Published: 2026-04-17 21:35 – Updated: 2026-04-17 21:35
VLAI?
Summary
Flowise: Unauthenticated TTS endpoint accepts arbitrary credential IDs — enables API credit abuse via stored credentials
Details

Summary

The text-to-speech generation endpoint (POST /api/v1/text-to-speech/generate) is whitelisted (no auth) and accepts a credentialId directly in the request body. When called without a chatflowId, the endpoint uses the provided credentialId to decrypt the stored credential (e.g., OpenAI or ElevenLabs API key) and generate speech.

Root Cause

// packages/server/src/controllers/text-to-speech/index.ts:58-64
} else {
    // Use TTS config from request body
    provider = bodyProvider
    credentialId = bodyCredentialId  // ← attacker-controlled credential ID
    voice = bodyVoice
    model = bodyModel
}

Docker Validation

POST /api/v1/text-to-speech/generate with arbitrary credentialId in body: endpoint processes request, sends SSE tts_start event, only fails when credential doesn't exist — proves code path runs without authentication.

Impact

  • Use victim's API keys (OpenAI, ElevenLabs, Azure, Google) without authorization
  • Burn API credits on the victim's account
  • Generate unlimited speech content at victim's expense
  • Combined with credential ID leak from Finding 2, this is trivially exploitable

Suggested Fix

Remove the TTS endpoint from WHITELIST_URLS or validate that the credential belongs to the chatflow being used:

// Only allow credentialId when it matches the chatflow's TTS configuration
if (!chatflowId) {
    return res.status(401).json({ message: 'Authentication required' })
}

References

  • packages/server/src/controllers/text-to-speech/index.ts lines 10-162
  • packages/server/src/utils/constants.ts line 41 (whitelist entry)

Credits

  • Shinobi Security - https://github.com/shinobisecurity
Severity ?
8.2 (High)
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.0.13"
      },
      "package": {
        "ecosystem": "npm",
        "name": "flowise"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-639"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-17T21:35:14Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\nThe text-to-speech generation endpoint (`POST /api/v1/text-to-speech/generate`) is whitelisted (no auth) and accepts a `credentialId` directly in the request body. When called without a `chatflowId`, the endpoint uses the provided `credentialId` to decrypt the stored credential (e.g., OpenAI or ElevenLabs API key) and generate speech.\n\n### Root Cause\n\n```typescript\n// packages/server/src/controllers/text-to-speech/index.ts:58-64\n} else {\n    // Use TTS config from request body\n    provider = bodyProvider\n    credentialId = bodyCredentialId  // \u2190 attacker-controlled credential ID\n    voice = bodyVoice\n    model = bodyModel\n}\n```\n\n### Docker Validation\n\n`POST /api/v1/text-to-speech/generate` with arbitrary `credentialId` in body: endpoint processes request, sends SSE `tts_start` event, only fails when credential doesn\u0027t exist \u2014 proves code path runs without authentication.\n\n### Impact\n\n- Use victim\u0027s API keys (OpenAI, ElevenLabs, Azure, Google) without authorization\n- Burn API credits on the victim\u0027s account\n- Generate unlimited speech content at victim\u0027s expense\n- Combined with credential ID leak from Finding 2, this is trivially exploitable\n\n### Suggested Fix\n\nRemove the TTS endpoint from `WHITELIST_URLS` or validate that the credential belongs to the chatflow being used:\n\n```typescript\n// Only allow credentialId when it matches the chatflow\u0027s TTS configuration\nif (!chatflowId) {\n    return res.status(401).json({ message: \u0027Authentication required\u0027 })\n}\n```\n\n---\n\n## References\n\n- `packages/server/src/controllers/text-to-speech/index.ts` lines 10-162\n- `packages/server/src/utils/constants.ts` line 41 (whitelist entry)\n\n## Credits\n- Shinobi Security - https://github.com/shinobisecurity",
  "id": "GHSA-5fw2-mwhh-9947",
  "modified": "2026-04-17T21:35:14Z",
  "published": "2026-04-17T21:35:14Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-5fw2-mwhh-9947"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/FlowiseAI/Flowise"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Flowise: Unauthenticated TTS endpoint accepts arbitrary credential IDs \u2014 enables API credit abuse via stored credentials"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.