GHSA-v2wj-q39q-566r: 
JavaScript vulnerability analysis and mitigation

Summary

The contents of files that are specified by server.fs.deny can be returned to the browser.

Impact

Only apps that match the following conditions are affected:

• explicitly exposes the Vite dev server to the network (using --host or server.host config option)
• the sensitive file exists in the allowed directories specified by server.fs.allow
• the sensitive file is denied with a pattern that matches a file by server.fs.deny

Details

On the Vite dev server, files that should be blocked by server.fs.deny (e.g., .env, *.crt) can be retrieved with HTTP 200 responses when query parameters such as ?raw, ?import&raw, or ?import&url&inline are appended.

PoC

1. Start the dev server: pnpm exec vite root --host 127.0.0.1 --port 5175 --strictPort
2. Confirm that server.fs.deny is enforced (expect 403): curl -i http://127.0.0.1:5175/src/.env | head -n 20 <img width="3944" height="1092" alt="image" src="https://github.com/user-attachments/assets/ecb9f2e0-e08f-4ac7-b194-e0f988c4cd4f" />
3. Confirm that the same files can be retrieved with query parameters (expect 200): <img width="2014" height="373" alt="image" src="https://github.com/user-attachments/assets/76bc2a6a-44f4-4161-ae47-eab5ae0c04a8" />