Buffer Overflow Examples
Some code examples for playing around with buffer overflows and shellcode.
Useful GDB commands
# show registers
info reg
# disassemble functions
disassemble <function_name>
# using breakpoints
## show code for main function
list main
## break at line 10
break 10
## step to next line
s
## continue
c
## step to next instruction
si
# print address of variable
print &buff
# show overview of current stack frame
x/100x $sp-200
# always show next instruction
display/i $pc
Extract shellcode from binary
for i in $(objdump -d shellcode |grep "^ " |cut -f2); do echo -n '\\x'$i; done; echo