vulnerability / NVI-00015376 / Revision 1
Budibase: S3 presigned URL endpoint authorization regression in v3.39.4 allows BASIC users to obtain S3 PutObject presigned URLs
GitHub lists this reviewed advisory for @budibase/server. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.7 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
@budibase/server
source listed<= 3.38.1
## Impact In Budibase v3.39.4, a regression in the authorization level for the S3 attachment upload endpoint allows any BASIC app user to obtain S3 PutObject presigned URLs. The endpoint uses TABLE/WRITE permission level instead of the intended BUILDER level defined in v3.39.3. Additionally, the controller does not pin the target bucket to the datasource's configured bucket, allowing writes to any S3 bucket the stored IAM credentials can access. ## Reproduction 1. As a BASIC app user, discover or obtain a valid S3 datasource ID within the app 2. Send a POST request: ``` POST /api/attachments//url Content-Type: application/json x-budibase-app-id: {"bucket": "target-bucket", "key": "malicious-file.html"} ``` 3. The response contains a valid S3 PutObject presigned URL 4. Use the presigned URL to upload arbitrary content to any writable S3 bucket in the IAM credential scope ## Root Cause The `/api/attachments/:datasourceId/url` route was changed from `authorized(BUILDER)` in v3.39.3 to `authorized(PermissionType.TABLE, PermissionLevel.WRITE)` in v3.39.4. BASIC users have TABLE/WRITE permissions by default, so they can call this endpoint. The controller at
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-xcx6-4f2g-hhgx ↗
GitHub Advisory Database · vendor advisory
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- Revision 1 ·
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