Vulnerability Check

Vulnerability check is to determine if the binary has some protection, such as ASLR, NX bit etc.
Some command lines in Linux allows us to check on this :

• checksec
• hardening-check
• rabin2 -I
• readelf -l [BINARY] | grep GNU_STACK : Read / Write / Execute
• file
• ldd : show the library that is linked dynamically to the binary

GDB commands

Some GDB commands are very useful for binary exploitation, it makes your life easier.

• info file
• info function
• print / p
• x/x 0x1337: print address
• x/s 0x1337: print string
• dissass : show the disassembly function
• x/15i $rip : show the next 15 instruction of the program
• set {int}0x1337 = 0x1234 : set value in an address

it is useful to automate some commands in GDB, we want to print the stack, print the register, print the next 4 instructions after each break point

GDB commands

To exploit binaries, it is useful to have some knowledge about x32 or x64 binary

• RDI : 1st argument
• RSI : 2nd argument
• RDX : 3rd argument
• RCX : 4th argument

Those registers are always placed before the instruction CALL.