Austin Howard fgsahoward
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| FROM base/archlinux:latest AS base | |
| RUN pacman -Sy --noconfirm binutils perl python libxcb clang emscripten git make cmake qbs | |
| ENV PATH="/usr/lib/emscripten:${PATH}" | |
| FROM base AS repos-configured | |
| COPY ./configure-qt5-repos.sh ./ | |
| RUN ./configure-qt5-repos.sh | |
| FROM repos-configured AS repos-built |
fgsahoward
/ function_prolog.s
Created
June 11, 2018 14:06
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| foo: | |
| # Begin function prolog | |
| push %ebp | |
| mov %esp, %ebp | |
| # End function prolog | |
| .... |
fgsahoward
/ function_epilog.s
Created
June 11, 2018 14:09
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| ... | |
| pop %ebp | |
| ret |
fgsahoward
/ function_call_stack_layout
Created
June 11, 2018 14:11
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| Before call to Function1: | |
| Register Value on stack Memory Address Notes | |
| ----------------------- | |
| | saved %eip | 0xbfffffd0 | |
| ----------------------- ---- | |
| %ebp -> | saved %ebp | 0xbfffffcc | | |
| ----------------------- | Main's stack frame | |
| | local variables | 0xbfffffc8 | |
fgsahoward
/ easy.c
Created
June 11, 2018 14:13
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| /** Easily exploitable Buffer Overflow for learning purposes | |
| * | |
| * Compilation: | |
| * gcc -fno-stack-protector -z execstack -m32 -o easy easy.c | |
| **/ | |
| #include <string.h> | |
| #include <stdio.h> | |
| #include <stdlib.h> |
fgsahoward
/ gdb_easy_disas_main
Created
June 11, 2018 14:16
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| $ gdb -q ./easy | |
| (gdb) disas main | |
| Dump of assembler code for function main: | |
| 0x0804843a <main+0>: lea 0x4(%esp),%ecx | |
| 0x0804843e <main+4>: and $0xfffffff0,%esp | |
| 0x08048441 <main+7>: pushl -0x4(%ecx) | |
| 0x08048444 <main+10>: push %ebp | |
| 0x08048445 <main+11>: mov %esp,%ebp | |
| 0x08048447 <main+13>: push %ecx | |
| 0x08048448 <main+14>: sub $0x14,%esp |
fgsahoward
/ gdb_easy_disas_vulnerable
Created
June 11, 2018 14:19
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| (gdb) disas vulnerable | |
| Dump of assembler code for function vulnerable: | |
| 0x08048404 <vulnerable+0>: push %ebp | |
| 0x08048405 <vulnerable+1>: mov %esp,%ebp | |
| 0x08048407 <vulnerable+3>: sub $0x408,%esp | |
| 0x0804840d <vulnerable+9>: mov 0x8(%ebp),%eax | |
| 0x08048410 <vulnerable+12>: mov %eax,0x4(%esp) | |
| 0x08048414 <vulnerable+16>: lea -0x400(%ebp),%eax | |
| 0x0804841a <vulnerable+22>: mov %eax,(%esp) | |
| 0x0804841d <vulnerable+25>: call 0x8048320 <strcpy@plt> |
fgsahoward
/ gdb_easy_breakpoint1
Created
June 11, 2018 14:21
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| (gdb) b *main+54 | |
| Breakpoint 1 at 0x8048470 | |
| (gdb) run hello | |
| Starting program: /tmp/easy/easy hello | |
| Breakpoint 1, 0x08048470 in main () | |
| Current language: auto; currently asm |
fgsahoward
/ gdb_easy_stack_examination1
Created
June 11, 2018 14:23
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| (gdb) info reg | |
| eax 0xbfffda82 -1073751422 | |
| ecx 0xbfffd8f0 -1073751824 | |
| edx 0xbfffd8f0 -1073751824 | |
| ebx 0x26eff4 2551796 | |
| esp 0xbfffd8c0 0xbfffd8c0 | |
| ebp 0xbfffd8d8 0xbfffd8d8 | |
| esi 0x8048490 134513808 | |
| edi 0x8048350 134513488 | |
| eip 0x8048470 0x8048470 <main+54> |
fgsahoward
/ gdb_easy_stack_examination2
Created
June 11, 2018 14:34
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| (gdb) x/xw $esp | |
| 0xbfffd8bc: 0x08048475 | |
| (gdb) si | |
| 0x08048405 in vulnerable () | |
| (gdb) | |
| 0x08048407 in vulnerable () | |
| (gdb) i r | |
| eax 0xbfffda82 -1073751422 | |
| ecx 0xbfffd8f0 -1073751824 | |
| edx 0xbfffd8f0 -1073751824 |
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