access payload variable with non default encoder

[joe2owl at yahoo.com (Joe Owler)]

How can I disable NOP sled ?

I  need the framework to generate shellcode and put it in the buffer. If i could adjust payload space variable in the 
runtime, that would probably do it, since there will be no need for nop sled.

I adjusted my badchars to contain all other characters than non alphanumeric, but now my payload won't generate, 
possibly due that restriction. 

[-] Exploit failed: No encoders encoded the buffer successfully.


Tried this as BadChars

"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x3a\x3b\x3c\x3d\x3e\x3f\x40\x5b\x5c\x5d\x5e\x5f\x60\x7b\x7c\x7d\x7e\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff"

I though nop sled would be all 0x90, that's why I didnt catch it in the first place.

Thanks,



----- Original Message ----
From: H D Moore <hdm at metasploit.com>
To: framework at metasploit.com
Sent: Monday, December 24, 2007 2:28:19 AM
Subject: Re: [framework] access payload variable with non default encoder


Those are nops being prepended to the payload.  If you don't want 
non-ascii characters in your nop sled, you need to add all of the 
restricted characters to the BadChars element.

-HD

On Sunday 23 December 2007, Joe Owler wrote:
> but when accessing payload it seems like it holds original payload as
> well as encoded one. Printing out payload.encoded, displays this








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