Fix #4132 - msfvenom undefined method fullname for NilClass

[wchen-r7]

See #4132

The bug is caused by a bad payload name.

• To verify: without the patch, if you do the following, you will get the undef method error:

./msfvenom -p payload/python/meterpreter/reverse_tcp -o LHOST=192.168.130.1 -f raw

• With the patch, it should say invalid payload.
• Now, try with a valid payload name: ./msfvenom -p python/meterpreter/reverse_tcp -o LHOST=192.168.130.1 -f raw
• It should show you the payload options this time.

[kernelsmith]

So in your second example, there should be no payload right?

[wchen-r7]

Yeah, never begin w/ "payload" Copy and paste fail.

[wvu]

I was gonna ask about that, but I guess @kernelsmith did! I tested without the "payload," anyway. However, I'm running into a separate bug:

wvu@kharak:~/metasploit-framework:(detached from upstream/pr/4161)$ ./msfvenom -p python/meterpreter/reverse_tcp -o LHOST=192.168.130.1 -f raw 
/home/wvu/metasploit-framework/lib/rex/text.rb:1400:in `compress': undefined method `gsub' for #<Array:0x000000055eae98> (NoMethodError)
        from /home/wvu/metasploit-framework/lib/msf/base/serializer/readable_text.rb:340:in `dump_payload_module'
        from /home/wvu/metasploit-framework/lib/msf/base/serializer/readable_text.rb:24:in `dump_module'
        from ./msfvenom:292:in `<main>'
wvu@kharak:~/metasploit-framework:(detached from upstream/pr/4161)$ 

Near as I can tell, the description is a string, not an array...

[wvu]

Doh! I merged #4160 and accidentally tagged it as #4161, which is this PR. Please see 0e772cc#commitcomment-8495600. Thanks!

[wchen-r7]

@wvu-r7 I'm not seeing what you're seeing:

aus-mac-1039:msf wchen$ git checkout upstream/pr/4161
HEAD is now at 7980a70... Fix #4132 - msfvenom undefined method fullname for NilClass
aus-mac-1039:msf wchen$ ./msfvenom -p python/meterpreter/reverse_tcp -o LHOST=192.168.130.1 -f raw 
Options for payload/python/meterpreter/reverse_tcp


       Name: Python Meterpreter, Python Reverse TCP Stager
     Module: payload/python/meterpreter/reverse_tcp
   Platform: Python
       Arch: python
Needs Admin: No
 Total size: 342
       Rank: Normal

Provided by:
    Spencer McIntyre

Basic options:
Name   Current Setting  Required  Description
----   ---------------  --------  -----------
LHOST                   yes       The listen address
LPORT  4444             yes       The listen port

Description:
  Run a meterpreter server in Python. Supported Python versions are 
  2.5 - 2.7 and 3.1 - 3.4. . Connect back to the attacker


aus-mac-1039:msf wchen$

[wvu]

@wchen-r7: Ruby 2.1.4?

[wchen-r7]

1.9.3.

[wvu]

I'm on 2.1.4. That might be it.

[wvu]

Works on 1.9.3. Merging.

[wchen-r7]

Oh boy, that breakage with 2.1.4 looks like something new. In 1.9.3 the description is a string, in 2.1.4 the description is an array that contains the string (description). I'll file another issue for this. Nice catch @wvu-r7

[wvu]

Yeah, as far as I can tell, it's unrelated to this fix, so it looks like a new issue is in order.

[wchen-r7]

Filed that one as: #4163