Vulnerability Development mailing list archives
Re: shellcoding on gentoo
From: "Mike Davis" <mdavis () imperfectnetworks com>
Date: Tue, 21 Feb 2006 14:36:06 -0500
ive written similar code recently using gentoo also, running on an amd 2200 XP:
i use GCC to build my assembler rather then nasm, could potentially be an issue there?
its also worth noting at&t syntax.. <snipped> //close: "\x89\xf3" // mov %esi,%ebx "\x31\xc0" // xor %eax,%eax "\xb0\x06" // mov $0x6,%al "\xcd\x80" // int $0x80 ;close "\x87\xf7" // xchg %esi,%edi "\x85\xc0" // test %eax,%eax "\x74\xf" // jz close //exit: "\x31\xc0" // xor %eax,%eax "\xb0\x01" // mov $0x1,%al "\xcd\x80" // int $0x80 ;exit <snipped>----- Original Message ----- From: "Borja" <padre () correo ugr es>
To: <vuln-dev () securityfocus com> Sent: Sunday, February 19, 2006 7:56 PM Subject: Re: shellcoding on gentoo
HiLot of ppl tell me that I did not proper zero the EAX register,so 3 MSB of eax corrupt trapping the syscall, but Its OK. I successfully run the shellcodes on a debian box,but in gentoo,allways SEGFAULT.There is it, a new log: ------------------------------------------------------------------------------------------------------------------------------------------------------ petalo shellcode # cat 1.asm BITS 32 ;exit() xor eax,eax xor ebx,ebx mov eax,1 int 0x80 petalo shellcode # nasm -g -f elf 1.asm petalo shellcode # ld 1.old: warning: cannot find entry symbol _start; defaulting to 00000000080480a0petalo shellcode # ./a.out Segmentation fault petalo shellcode # gdb -q a.out Using host libthread_db library "/lib/libthread_db.so.1". (gdb) break 1 Breakpoint 1 at 0x80480a0: file 1.asm, line 1. (gdb) r Starting program: /root/code/shellcode/a.out Program terminated with signal SIGSEGV, Segmentation fault. The program no longer exists. You can't do that without a process to debug. (gdb) q petalo shellcode #Linux petalo 2.6.12-gentoo-r6 #9 Sat Dec 24 14:37:56 CET 2005 i686 AMD Athlon(tm) XP 1600+ AuthenticAMD GNU/Linux------------------------------------------------------------------------------------------------------------------------------------------------------ I cant explain why SIGFAULT.I did not edit any advanced kernel configurations rather than snd card and ethernet.Thanks in advance.
Current thread:
- Re: shellcoding on gentoo apriori (Feb 01)
- <Possible follow-ups>
- Re: shellcoding on gentoo nonexistent (Feb 07)
- Re: shellcoding on gentoo Borja (Feb 21)
- Re: shellcoding on gentoo Mike Davis (Feb 21)
- Re: shellcoding on gentoo DJ Ether (Feb 21)
- Re: shellcoding on gentoo Mike Davis (Feb 21)
- Re: shellcoding on gentoo security (Feb 22)