[Challenge 5:] freeSSHd SFTP Authentication Bypass vulnerability

IP ADDRESS: 172.19.19.2

OPERATING SYSTEM: Windows 7 Ultimate

Tools Used:

• NMAP
• HPING3
• NIKTO
• NESSUS
• HYDRA
• METASPLOIT

Methodology:

NMAP

nmap -sS -sU -T4 -A -v -PE -PP -PS80,443 -PA3389 -PU40125 -PY -g 172.19.19.2

HPING3

hping3 --scan 1-1000 -S 172.19.19.2

NIKTO

Nessus

VISIT IP ADDRESS IN BROWSER

HYDRA

METASPLOIT

The vulnerability that we used was the freeFTPd / freeSSHd SFTP Authentication Bypass vulnerability. The freeFTPd or freeSSHd has an authentication bypass vulnerability. Authentication can be bypassed by opening an SSH channel before any credentials are provided. A remote, unauthenticated attacker could exploit this to login without providing credentials.

msf > search windows/ssh/freesshd_authbypass

Vulnerabilities and Recommendations:

• MS14-066: Vulnerability in Schannel Could Allow Remote Code Execution - The remote Windows host is affected by a remote code execution vulnerability due to improper processing of packets by the Secure Channel (Schannel) security package. An attacker can exploit this issue by sending specially crafted packets to a Windows server.

  • SOLUTION: Microsoft has released a set of patches for Windows 2003, Vista, 2008, 7, 2008 R2, 8, 2012, 8.1, and 2012 R2.

• MS15-034: Vulnerability in HTTP.sys Could Allow Remote Code Execution - The version of Windows running on the remote host is affected by an integer overflow condition in the HTTP protocol stack (HTTP.sys) due to improper parsing of crafted HTTP requests. An unauthenticated, remote attacker can exploit this to execute arbitrary code with System privileges.

  • SOLUTION: Microsoft has released a set of patches for Windows 7, 2008 R2, 8, 8.1, 2012, and 2012 R2