Budibase is an open-source low-code platform. Prior to 3.38.2, the file upload endpoint POST /api/attachments/process does not enforce active-content restrictions for authenticated users. The checks for dangerous file extensions are conditionally wrapped inside if (isPublicUser) or if (isPublicUser || !env.SELF_HOSTED), meaning any authenticated builder can upload executable web content — SVG files with inline <script> tags, HTML pages with JavaScript, .js modules — which are then stored in the object store (MinIO/S3) with their correct MIME types. When the resulting signed URL is opened by any app user, the browser executes the payload. Impact is persistent stored XSS over all application end users. This vulnerability is fixed in 3.38.2.

Affected: npm: budibase

### Summary The file upload endpoint `POST /api/attachments/process` does not enforce active-content restrictions for authenticated users. The checks for dangerous file extensions (`html`, `svg`, `js`, `php`, etc.) are conditionally wrapped inside `if (isPublicUser)` or `if (isPublicUser || !env.SELF_HOSTED)`, meaning any authenticated builder can upload executable web content — SVG files with inline `<script>` tags, HTML pages with JavaScript, `.js` modules — which are then stored in the object store (MinIO/S3) with their correct MIME types (`image/svg+xml`, `text/html`, `application/javascript`). When the resulting signed URL is opened by any app user, the browser executes the payload.

Impact is **persistent stored XSS** over all application end users.

### Details The vulnerability exists in a single handler function uploadFile shared by two routes, located in packages/server/src/api/controllers/static/index.ts (lines 93–179).

Route definitions (packages/server/src/api/routes/static.ts):

POST /api/attachments/process → authorized(BUILDER) POST /api/attachments/:tableId/upload → authorized(PermissionType.TABLE, PermissionLevel.WRITE) Both routes invoke the same uploadFile function. The second endpoint is accessible to any authenticated app user (BASIC or POWER role) who has been granted WRITE on any table — not just builders.

### PoC

### Prerequisites

- Budibase self-hosted Docker deployment, any version ≤ 3.30.6 - An account with Builder role (does…

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Budibase ausnutzen, um Administratorrechte zu erlangen, Sicherheitsmaßnahmen zu umgehen, Cross-Site-Scripting-Angriffe durchzuführen oder vertrauliche Informationen offenzulegen.