This is bit of a simple challenge but the concept here is the very important and might be bit difficult to grasp. Here the code part is interesting as the developer in this case forgets to pass on the reference to the variable which we can weaponize and take control of the program. Without the reference or & sign the scanf function treats the variable as a pointer and tries to write information to that address where is “pointing to”. Thus we can overwrite any address in the memory with some other information.

Rappel is a wonderful for understanding the basics of assembly language. Initially assembly language is quite challenging to understand for the programmer as all these registers are quite confusing. Specially it becomes more difficult because the programmer is now limited to using only handful of variables where as in other languages, the number declaring variable appears to be unlimited.

After we download and run the rappel, we can see that

display

functions

flags

To view the flags, use the command below:

info reg eflags

breaks

stack 

source

https://cheatography.com/superkojiman/cheat-sheets/gdb-pwndbg/

motivations and technologies used here

details for log4j exploit