June 2020
Intermediate to advanced
423 pages
7h 58m
Chinese
Content preview from Kali Linux学习手册
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
140
｜
第
4
章
函数。比如，此输入可能是操作系统命令或
SQL
代码。如果程序员在对其操
作之前没有进行适当的输入验证，则可能会发生错误。
访问控制
访问控制的概念有一点笼统。出现该问题的一个场景是程序被赋予其函数所
需更多的权限或特权。比如，以
root
身份运行的任何程序都可能存在问题。
如果代码可以被漏洞利用，比如，验证输入不当或缓冲区溢出，攻击者就可
以通过
root
权限做任何事。
这并不严格局限于以
root
身份运行的程序。任何程序都以程序所有者的权限
运行。如果程序所有者有权访问系统中的任何资源，则利用该程序可以使得
攻击者访问上述资源。这种攻击可能导致权限升级：用户可以访问系统内正
常状态下无法访问的内容。
通过要求在应用程序内进行权限认证，至少可以在一定程度上缓解这一特定
问题。至少，这是攻击者利用程序之前需要清除的障碍，他们必须通过直接
攻击或者猜测密码来规避身份验证。有时候，最好的办法就是让访问过程变
得更繁琐。
本地漏洞
本地漏洞需要获得对系统某种程度的访问权限。本地漏洞的目标不是获得访
问权限。在利用本地漏洞之前，必须已经获得访问权限。利用本地漏洞的思
路通常是访问攻击者无法接触的内容。
本地漏洞的特点是它们可以出现在系统上的任何程序中。这包括运行在后台
而没有直接和用户打交道的服务程序，通常也称为守护程序，以及用户可以
访问的任何其他程序。用于设置用户标识符（
setuid
）的程序
passwd
就是如此，
它允许任何用户运行它并临时获得
root
权限。这是必要的，因为更改用户的
密码需要更改只有
root
用户才能写入的文件。如果我想修改密码 ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.