博客
关于我
攻防世界-pwn-200-Writeup
阅读量:572 次
发布时间:2019-03-09

本文共 2103 字,大约阅读时间需要 7 分钟。

pwn-200 Vulnerability Analysis

Overview of the Issue

The sub_8048484 function in the provided code is vulnerable to a stack overflow attack. This function reads data into a buffer using read(0, &buf, 0x100u) which can cause a stack overflow if not handled correctly. The vulnerable code is:

ssize_t sub_8048484() {    char buf;    setbuf(stdin, &buf);    return read(0, &buf, 0x100u); // Overflow here}

Exploiting the Vulnerability

To exploit this vulnerability, we need to analyze how the stack buffer works. The function uses a single-byte buffer and attempts to read data directly into the stack without proper bounds checking. Exploiting this requires understanding how the stack is structured and how overflow affects it.

The key to this exploit is to identify the location where the return address is stored after the stack overflow. By overwriting the return address, we can control the program's flow and gain arbitrary code execution.

Finding libc Base

Using the provided exploit code, the following steps can be taken:

  • Identify the libc base

    After successful exploitation, we can leak the memory address of the write function from libc6-i386_2.23-0ubuntu11_amd64.so. This is done by sending a crafted payload that forces the program to use the overwritten return address as the write function's target.

  • Calculate libc_base

    Once the write function's address is identified, we subtract the libc.symbols['write'] value from it to get the base address of libc.

  • Identify system() Function

    With libc_base, we can find the system() function's address and eventually gain a shell using /bin/sh.

  • Exploit Execution

    The provided remote exploit code demonstrates how to:

  • Bypass stack guard pages by sending a payload that triggers the stack overflow.
  • Update the return address to point to the write function's address.
  • Read the leaked memory address to find the write function's base, hence determining the libc_base.
  • Use system() for shelling out by leveraging binsh from libc.
  • By following these steps, a full RDI (Remote Differential Exploit) can be achieved, allowing for full control over the system.

    转载地址:http://amppz.baihongyu.com/

    你可能感兴趣的文章
    mysql并发死锁案例
    查看>>
    MySQL底层概述—1.InnoDB内存结构
    查看>>
    MySQL底层概述—2.InnoDB磁盘结构
    查看>>
    MySQL底层概述—3.InnoDB线程模型
    查看>>
    MySQL底层概述—4.InnoDB数据文件
    查看>>
    MySQL底层概述—5.InnoDB参数优化
    查看>>
    MySQL底层概述—6.索引原理
    查看>>
    MySQL底层概述—7.优化原则及慢查询
    查看>>
    MySQL底层概述—8.JOIN排序索引优化
    查看>>
    MySQL底层概述—9.ACID与事务
    查看>>
    Mysql建立中英文全文索引(mysql5.7以上)
    查看>>
    mysql建立索引的几大原则
    查看>>
    Mysql建表中的 “FEDERATED 引擎连接失败 - Server Name Doesn‘t Exist“ 解决方法
    查看>>
    MySQL开源工具推荐,有了它我卸了珍藏多年Nactive!
    查看>>
    MySQL异步操作在C++中的应用
    查看>>
    MySQL引擎讲解
    查看>>
    Mysql当前列的值等于上一行的值累加前一列的值
    查看>>
    MySQL当查询的时候有多个结果,但需要返回一条的情况用GROUP_CONCAT拼接
    查看>>
    MySQL必知必会(组合Where子句,Not和In操作符)
    查看>>
    MySQL必知必会总结笔记
    查看>>