cidr-finder

Overview

A command line tool to retrieve CIDR info of a target during security engagements

What is cidr-finder ?

It is rudimentary bash script which acts a wrapper around https://api.bgpview.io to retrieve only CIDR info of a target. CIDR refers to Classless Inter-Domain Routing which is a method for allocating IP addresses and for IP routing.

From this, one can identify IP Address scope of a target enabling them broaden their attack surfaces by mapping endpoints at those addresses.This is true especially for large corporation who purchase an IP block from a RIR(Regional Internet Registries).

Why cidr-finder ?

During my engagements in order to get a good overview of my target, i normally prefer to start with its IP Address scope and from there map down domains, subdomains among other entities related to the target.

Dependencies

You need to have curl and jq installed.

To install, use the package-manager provided in your system. On most Linux distributions curl is installed by default. By default jq is not installed but present in the repository of your Distro

Debian & Ubuntu

sudo apt-get install curl jq

Arch

sudo pacman -S curl jq

Installation

git clone https://github.com/BabyBabaBabu/cidr-finder
cd cidr-finder
chmod +x cidr-finder.sh

Usage

./cidr-finder [option] {parameter}

By default cidr-finder saves output to a folder name results/ within the script directory.

Options

Options:
        -o <org name>   Query by Organization name.
        -d <domain>     Query by Domain
        -i <ip address> Query by IP Address
        -a <AS Number>  Query by ASN
        -h              Display this help message.

Examples

Examples:
        ./cidr-finder.sh -o hackerone
        ./cidr-finder.sh -d hackerone.com
        ./cidr-finder.sh -i 104.16.99.52
        ./cidr-finder.sh -a AS15169

Special Thanks to BGPView for exposing their API to the public for free.