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Showing posts from December 24, 2017

Use SSH Local Port Forwarding to Pivot into Restricted Networks

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SSH is a powerful tool with more uses than simply logging into a server. This protocol, which stands for Secure Shell, provides X11 forwarding, port forwarding, secure file transfer, and more. Using SSH port forwarding on a compromised host with access to a restricted network can allow an attacker to access hosts within the restricted network or pivot into the network. In this article, we'll look at one of the SSH port forwarding options, local port forwarding. Since this can be somewhat confusing, I'd like to talk a little bit about the idea of port forwarding first. Why Port Forwarding Is Important When we think of port forwarding, we usually think of it in the terms of a router. With a typical home internet setup, the router is connected to the WAN (wide area network), and it will have an IP address assigned by the ISP (internet service provider). On the other side of the router, you have your LAN (local area network). Hosts within the LAN are generally assigned IP a

Detect Misconfigurations in 'Anonymous' Dark Web Sites with OnionScan

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Configuring onion services for the first time can be tricky. A surprising number of system administrators make seemingly trivial mistakes that ultimately lead to catastrophic cases of de-anonymizing supposedly  anonymous  sites on the dark web.  OnionScan  is a tool designed to identify common misconfigurations in onion services and aid us in understanding how to fix them. As security researcher  @x0rz  demonstrated in an  article on securing onion services , websites are often de-anonymized all too easily. He utilized software such as  cURL , a command-line tool used for transferring data using various protocols, to collect HTTP response headers for later  Shodan  queries. All of the methods x0rz used to de-anonymize the onion services should have been ineffective if basic safeguards were taken by the site owners. System administrators need to take better precautions to prevent their websites from being vulnerable to server fingerprinting and enumeration. And that's where On