This session starts with a discussion on concurrent servers and their advantages. What happens when multiple echo client accesses an iterative echo server. A concurrent echo server is designed using three techniques. Using fork(), then using pthread_create() and finally using the famous select() system call. The need of concurrent clients is also discussed in the end.

Email: arif@pucit.edu.pk
Example Codes: https://bitbucket.org/arifpucit/spvl-repo/src

This is a continuation of Video Session 38. In this session we will discuss what are shell codes and how these are used. Four different ways of writing/getting shell codes are discussed. First of all how we can write shell codes from scratch using Assembly Language is discussed, and then the same is used in a stand alone C-program. Secondly different Internet archives are explored to get shell codes. Thirdly writing your shell codes using pwn tools, and finally writing your shell codes using msfvenom and using them in stand alone C-program. Proof of all these concepts are shown using hands on a Linux terminal and using ipython
Email: arif@pucit.edu.pk
Example Codes: https://bitbucket.org/arifpucit/spvl-repo/src

This is a series of three videos, which gives a quick start up on different exploitation and mitigation techniques for the buffer overflow vulnerability. The session start with an overview of a classic stack based buffer overflow. How a stack based buffer overflow can be exploited? Exploit mitigation techniques. The architecture of x86_64, its assembly and function calling convention. Installing and using PEDA. Finally a practical sample program is shown as to how to change the control of flow of execution of a program using PEDA.

Email: arif@pucit.edu.pk
Example Codes: https://bitbucket.org/arifpucit/spvl-repo/src

This is a continuation of Video Session 39. In this session we will see ways of finding vulnerabilities in executables. Crafting an input string to vulnerable programs to shift the control of flow of execution to some other part in the code section. Injecting shell code via input string and transferring control of flow to it. We will learn how to inject shell code via environment variables and transferring control of flow to it. Addressing problems that most of the students face when exploiting vulnerable programs outside gdb. Exploiting a vulnerable echo server executing on a remote machine and creating a tcp bind shell and a reverse tcp shell. A discussion on bypassing exploit mitigation techniques used by most modern operating systems and compilers.

Email: arif@pucit.edu.pk
Example Codes: https://bitbucket.org/arifpucit/spvl-repo/src