![]() Now we need to create a reverse tcp shellcode to use it in our exploit. Offset with CALL ESP: 0圆8d652el Building the Exploit create exploit.py I am going to use the first one with JMP ESP and also the first address with CALL ESP. Now that we found many addresses which contains CALL ESP and JMP ESP instructions in it. Immunity Command: !mona find -s “\xff\xe4” -m Qt5Core.dll (or) !mona find -s “\xff\xd4” -m Qt5Core.dll JMP ESP CALL ESP Now we need to find the offsets in Qt5Core.dll, at which FFE4 or FFD4 is present so that we can use that offset address in the exploit. We use a tool called msf-nasm_shell to find these opcodes. To do that, first we need to find the OPcode for JMP ESP and CALL ESP. Now we are going to find the offsets in Qt5Core.dll which contains the Instruction “JMP ESP” (jump to the address at stack pointer) or “CALL ESP” (call the address at stack pointer). We are interested in “Qt5Core.dll”, because it is unprotected.Binary protections ASLR, DEP, SafeSEH are flagged false for Qt5Core.dll. In which many of them are protected with some sort of protections like ASLR, DEP. It Shows a table all the modules loaded in the current process with their binary protections,base addresses etc. In command tab at the bottom of Immunity Debugger window. Restart Immunity Debugger and attach Cloudme with it. In this step, we are going to find the right modules (DLLs and EXEs invoked) to attack, i.e., we need an unprotected module (Non-ASLRed, No DEP) to attack.įor this, we need a plugin called “Mona” for Immunity debugger.Īnd go to Immunity debugger’s installation folder, then save it under “P圜ommands” folder. Note: you should provide the same length value to the -l flag which is used with the pattern creation (msf-pattern_create) The Next step is to find the appropriate modules (DLLs and EXEs invoked into cloudme’s process) to attack. Yay! We have Identified the correct offset that overwrites EIP! ![]() Use the value of EIP register(316A4230) and query it to msf-pattern_offset. Now the next step is, identifying the correct offset using a tool called “msf-pattern_offset” Open Cloudme, Immunity again and attach Cloudme with Immunity Debugger. ![]() Now We need to use the pattern in fuzz.py and run it against cloudme, then notice the EIP. Here I am saving the pattern to a text file, so that it can be accessible in Windows 10 machine also. It will create a long string with random characters. We Successfully Crashed the application! Now we need to identify the correct offset that overwritten the EIP register.įor this we need to use a tool called “msf-pattern_create” which is a part of Metasploit Framework. Hit f9, we can’t continue the program because of SEGMENTATION FAULT. Sending 3000 A’s to port 8888 127.0.0.1:8888Īfter running the fuzz.py program against cloudme, we can see the access violation and notice that the EIP register has been overwritten with 0x41414141 which is AAAA in hex. Open Immunity Debugger and attach CloudMe, hit f9 to run cloudme inside the debugger. In the directory “cloudme_exploit”, I created a python file “fuzz.py”. I have created a network share between my Kali Machine and Windows 10 machine. Yes! It’s being listening on port 8888! Now Lets hit it with huge data and make cloudme to crash. Netstat -ano | findstr 8888 cmd.exe checking for listening port 8888 Lets Go! Cloudme Listens on port 8888, lets open cloudme app and make sure that is listens on port 8888 So, basically we are developing a real exploit and attacking a real app. There are some executables/apps like “vulnserver” that are intentionally built to be vulnerable for educational purposes, but this is a real life application. This demo will help guys who are preparing for OSCP or equivalent Certifications and also help guys (like me!) who wanna learn advanced hacking and exploit development. This is a Local Privilege Escalation Vulnerability This buffer overflow vulnerability was patched and the exploit is released publicly in 2018 (CVE-2018–6892). In this Post, I am gonna demonstrate windows Stack buffer overflow and exploit development in CloudMe 1.11.2.
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