SSH-MITM - ssh audits made simple

ssh man-in-the-middle (ssh-mitm) server for security audits supporting
publickey authentication, session hijacking and file manipulation

Contributors

Introduction
Features
Installation
Quickstart
Session hijacking
Phishing FIDO Tokens
Contributing
Contact

Introduction

SSH-MITM is a man in the middle SSH Server for security audits and malware analysis.

Password and publickey authentication are supported and SSH-MITM is able to detect, if a user is able to login with publickey authentication on the remote server. This allows SSH-MITM to accept the same key as the destination server. If publickey authentication is not possible, the authentication will fall back to password-authentication.

When publickey authentication is possible, a forwarded agent is needed to login to the remote server. In cases, when no agent was forwarded, SSH-MITM can rediredt the session to a honeypot.

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Features

publickey authentication
- accept same key as destination server
- Phishing FIDO Tokens (Information from OpenSSH)
hijacking and logging of terminal sessions
store and replace files during SCP/SFTP file transferes
port porwarding
- SOCKS 4/5 support for dynamic port forwarding
intercept MOSH connections
audit clients against known vulnerabilities
plugin support

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Installation

SSH-MITM can be installed as a Flatpak, Ubuntu Snap, AppImage and PIP-Package.

Community-supported options include installations via `Nix and running on Android devices.

Install from Flathub:

flatpak install flathub at.ssh_mitm.server
flatpak run at.ssh_mitm.server

Install from Snap store:

sudo snap install ssh-mitm

Install as AppImage:

wget https://github.com/ssh-mitm/ssh-mitm/releases/latest/download/ssh-mitm-x86_64.AppImage
chmod +x ssh-mitm*.AppImage

Install python package:

python3 -m pip install ssh-mitm

For more installation methods, refer to the SSH-MITM installation guide.

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Quickstart

To start SSH-MITM, all you have to do is run this command in your terminal of choice.

ssh-mitm server --remote-host 192.168.0.x

Now let's try to connect. SSH-MITM is listening on port 10022.

ssh -p 10022 testuser@proxyserver

You will see the credentials in the log output.

INFO     Remote authentication succeeded
    Remote Address: 127.0.0.1:22
    Username: testuser
    Password: secret
    Agent: no agent

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Session hijacking

Getting the plain text credentials is only half the fun. When a client connects, the ssh-mitm starts a new server, which is used for session hijacking.

INFO     ℹ created mirrorshell on port 34463. connect with: ssh -p 34463 127.0.0.1

To hijack the session, you can use your favorite ssh client.

ssh -p 34463 127.0.0.1

Try to execute somme commands in the hijacked session or in the original session.

The output will be shown in both sessions.

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Phishing FIDO Tokens

SSH-MITM is able to phish FIDO2 Tokens which can be used for 2 factor authentication.

The attack is called trivial authentication (CVE-2021-36367, CVE-2021-36368) and can be enabled with the command line argument --enable-trivial-auth.

ssh-mitm server --enable-trivial-auth

Using the trivial authentication attack does not break password authentication, because the attack is only performed when a publickey login is possible.

Video explaining the phishing attack:
Click to view video on vimeo.com

Downlaod presentation slides

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Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!