Re: Any advice?
Posted: Mon Mar 25, 2024 5:10 am
Hey y’all. Last week we pulled a couple of all nighters investigating this, and this is what we’ve obtained so far in order to eventually prevent ourselves from getting PWNed. The program was a little janky when compiled as 32-bit, so we’ve made a safe bet to remake it as a 64-bit executable (upgrades people, upgrades!) We’ve analyzed it thoroughly… and surprise! Contrary to our expectations, there seems to be 8 bytes of padding between the buffer and correct_or_not. Also, we’ve tested the com server with netcat, telnet, as well as our own programs using sockets, and all of them seem to communicate successfully!
Oh, and one last thing: the JSON decoder in the program seems to be nitpicky beyond our expectations. If you test it yourself, make sure to send the message in this format exactly: double quotes around values, no outermost quotes around the braces. {“code”: “<your message here!>”}
Note that if you use the echo command to print this message, you must escape the double quotes with a backslash (\”).
Oh, and one last thing: the JSON decoder in the program seems to be nitpicky beyond our expectations. If you test it yourself, make sure to send the message in this format exactly: double quotes around values, no outermost quotes around the braces. {“code”: “<your message here!>”}
Note that if you use the echo command to print this message, you must escape the double quotes with a backslash (\”).