Phần này sẽ có một quan điểm khác với hầu hết khi chúng ta nói về lịch sử của hacking. Các trường hợp của quá khứ cũng đã công bố công khai và có nhiều tài nguyên mô tả trường hợp này và các cá nhân tham gia. Thay vào đó, phần này sẽ tiếp cận lịch sử của hacker bằng cách thảo luận về sự tiến hóa của các kỹ thuật được sử dụng bởi tin tặc. | Chapter 13 Hacker Techniques 239 HISTORICAL HACKING TECHNIQUES This section is going to take a different perspective than most when we talk about the history of hacking. The cases of the past have been well publicized and there are many resources that describe such cases and the individuals involved. Instead this section will approach the history of hacking by discussing the evolution of techniques used by hackers. As you will be able to see many cases of successful hacking could be avoided by proper system configuration and programming techniques. Open Sharing When the Internet was originally created the intent was the open sharing of information and collaboration between research institutions. Therefore most systems were configured to share information. In the case of Unix systems the Network File System NFS was used. NFS allows one computer to mount the drives of another computer across a network. This can be done across the Internet just as it can be done across a Local Area Network LAN . File sharing via NFS was used by some of the first hackers to gain access to information. They simply mounted the remote drive and read the information. NFS uses user ID numbers UID to mediate the access to the information on the drive. So if a file were limited to user JOE UID 104 on its home machine user ALICE UID 104 on a remote machine would be able to read the file. This became more interesting when some systems were found to allow the sharing of the root file system including all the configuration and password files . In this case if a hacker could become root on a system and mount a remote root file system he could change the configuration files of that remote system see Figure 13-2 . Open file sharing might be considered a serious configuration mistake instead of a vulnerability. This is especially true when you find out that many operating systems including Sun OS shipped with the root file system exportable to the world read write this means that anyone on any .
