Attackers might target /etc/passwd on Linux or boot configuration files on Windows.
In Node.js, the situation is more complex. Node.js . However, because Node.js has access to the entire file system through its fs module, it's possible to implement this functionality, and many third-party libraries have done exactly that.
From a cybersecurity perspective, seeing a string that attempts to "fetch" a "file" scheme is a major red flag. It points directly to a vulnerability known as . fetch-url-file-3A-2F-2F-2F
: When working within a mobile or browser environment, a common workaround for the file:// restriction is to bypass it entirely. Instead of trying to force the Fetch API to read a local file, you can spin up a lightweight local web server (e.g., using Python's http.server module or a library like http-server for Node.js) and serve the assets over http://localhost:8080/pages/log.html . This is often the most straightforward and robust solution for production applications.
fetch-url-file-3A-2F-2F-2F -> fetch url file:/// Attackers might target /etc/passwd on Linux or boot
from urllib.parse import unquote encoded_str = '3A-2F-2F-2F' decoded_str = unquote(encoded_str.replace('-', '%')) # Result: :/// Use code with caution. Copied to clipboard 2. Fetching with the file:// Scheme
Trying to fetch a file:/// path in JavaScript triggers an error. However, because Node
Thus, fetch-url-file-3A-2F-2F-2F essentially refers to using the fetch() API in JavaScript to request a resource from the via the file:/// protocol.
Scripts that move files from one folder to another using URI-based protocols.
– A custom URI scheme or malformed URL where the “scheme” is fetch-url-file , followed by three slashes (an absolute local path indicator, similar to file:///etc/passwd ).
