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Advanced area of attack and defense world experts - stack2 Look at the title, nothing 1, Analysis file checksec It is found that there is stack overflow protection, which has not been seen before. There may be new knowledge points. Run file It seems to be a program for inputting numbers to calculate the average value. ida open unsig ...

1.ret2shellcode Quote ciscn_ 2019_ n_ five Open the main function and find that get is still a stack overflow, but shift has no bin and system, and no protection is turned on. When a name variable is opened, it is found to exist on the bss side. Therefore, you want to write the name directly to shellcode, and adjust get to the name func ...

Common formatting string functions Output: functionBasic introductionprintfOutput to stdoutfprintfOutput to the specified FILE streamvprintfFormat the output to stdout according to the parameter listvfprintfFormat the output to the specified FILE stream according to the parameter listsprintfOutput to stringsnprintfOutputs the specified number ...

preface Vegetable chicken summary, if there is something wrong, I hope you can give advice in time to avoid harming people's children. 0x1: basic knowledge: Everyone must know the problem solved by stack migration technology - the overflow length is not enough and can only cover the return address. As for the length of the rop chain to ...

What is a format character vulnerability The format string function can accept a variable number of parameters, take the first parameter as the format string, and parse the parameters according to it. Generally speaking, the format string function is to convert the data represented in computer memory into a human readable string format. Al ...

This problem is done in two ways: one is to modify the got table, and the other is to modify the return value to control the execution flow. IDA analysis There is an obvious format string vulnerability, but it is on the bss segment To sum up, the processing method of 32-bit format string in bss segment is to find an ebp like stack register, ...

Foreword: I just started the core problem recently, so I'll learn from ctfwiki here. Don't spray... The first step is classic... If the title is not given to vmlinux, it can be extracted through extract vmlinux. See start SH finds that kalsr randomization is enabled, and the base address needs to be leaked. This is very similar to the pwn pro ...

Fancy stack overflow reference resources: https://ctf-wiki.org/pwn/linux/user-mode/stackoverflow/x86/fancy-rop/#2018-over reference resources: https://www.yuque.com/hxfqg9/bin/erh0l7 reference resources: https://ctf-wiki.org/pwn/linux/user-mode/stackoverflow/x86/fancy-rop 1. Principle 1.1 stack pivoting Stack pivoting is turned into s ...