Curl-url-file-3a-2f-2f-2f ^hot^ Info

| Literal | Encoded | Detection Difficulty | |---|---|---| | file:// | %66%69%6C%65%3A%2F%2F | High | | file:// | file%3A%2F%2F | Moderate | | ../ | %2E%2E%2F | Moderate |

[Attacker] -> Sends URL Parameter: "file-3A-2F-2F-2Fetc/passwd" -> [Vulnerable Web App] -> Executes Internal Curl Command -> Exfiltrates Local File Data

: If a URL is improperly formatted or contains illegal characters, typically returns Exit Code 3 ("URL using bad/illegal format"). Stack Overflow Example Scenarios Fetching a local file curl file:///etc/passwd curl-url-file-3A-2F-2F-2F

The %3A sequence is a , and the %2F sequence is a forward slash . When fully decoded, the keyword resolves to:

: Indicate the beginning of the authority (host) component. | Literal | Encoded | Detection Difficulty |

SSRF occurs when an attacker forces a server-side application to make unauthorized requests. If an attacker leverages the file:// handler via cURL on a vulnerable server, they can map out the internal hosting environment, read internal metadata endpoints, and compromise the underlying infrastructure. How to Secure Your Applications

: Developers can use cURL to pull data from a local JSON file to simulate an API response during offline development. Automation SSRF occurs when an attacker forces a server-side

When decoded, %3A%2F%2F%2F converts directly to :/// . Therefore, the raw intent behind the keyword is executing a command formatted as: curl file:///path/to/file . How the file:// Protocol Works in Curl

: Saves the output of a URL to a specific local file. -O : Saves the file using its remote name. -I : Fetches only the headers or metadata of a file or URL.