If a web application allows a user to input a URL, and that application passes the input to curl , an attacker could use file-3A-2F-2F-2F (or file:/// ) to read sensitive files from the server, such as: /etc/passwd (User accounts) ~/.ssh/id_rsa (Private SSH keys) /proc/self/environ (Environment variables)

In cURL, file:/// is used to read from the local filesystem.

Decoding cURL SSRF Payloads: The Case of file-3A-2F-2F-2F Content:

This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. URL syntax - curl

: Scripts can use the same cURL command to fetch either a remote resource or a local configuration file, providing a unified interface for data handling.

The third slash / represents the root directory of the local system. Therefore, file:/// means "look at the absolute root path of this machine." 3. The Encoding: %3A and %2F

Before diving into the world of curl-url-file-3A-2F-2F-2F , let's take a brief look at what curl is. curl is a free and easy-to-use command-line tool that allows users to transfer data to and from a web server using various protocols. It supports a wide range of protocols, including HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, and more. curl is widely used by developers, sysadmins, and web users alike for tasks such as downloading files, testing web APIs, and uploading files to servers.

Although the specific report you requested does not exist, the underlying concept raises several security concerns relevant to software development and system administration:

So, 3A-2F-2F-2F decodes to :/:/// .