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A Real World Attack: wu-ftp. Description. There have many intrusion accident happened in day. Do you know what technique that crackers can intrude your web server, mail server and ftp server.
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Description • There have many intrusion accident happened in day. Do you know what technique that crackers can intrude your web server, mail server and ftp server. • Today, this exercise will guide you through the process of discoveringa vulnerable system, exploitingthe vulnerability, and installing software to cover your tracks.
Purpose • Located a vulnerable system • Exploit that vulnerability to gain a root shell • Installed a RootKit • Access the system via the RootKit
Principle and Pre-Study (I) • CERT Advisory CA-1999-13 Multiple Vulnerabilities in WU-FTPD • MAPPING_CHDIR Buffer Overflow • Message File Buffer Overflow • SITE NEWER Consumes Memory • http://www.cert.org/advisories/CA-1999-13.html
Principle and Pre-Study (II) • What is Buffer overflow? A type of programmatic flaw that is due to a programmer allowing for an unbounded operation on data.
Required Facilities • WARNING: • This process of cracking a system is only tested in internal network. • Do not actual exploit on unprivileve host • Hardware • PC or Workstation with UNIX-like system • Software • Wu-ftp 6.2.0 • RootKits and Buffer Overflow Program
Step (I): reconnaissance and scanning Use “nmap” for system scanning Test the account of anonymous
Step (II): exploit the target Decompress the buffer overflow file and compile it List the usage of this tool
Step (III): cracking Execute the buffer overflow on target host Got the root right
Step (IV) • Download the rootkit from outside and install it checking the login user Download the tool from another victim Decompress the rootkit Execute the rootkit
Step (V): auto-patch the victim the default login password change the system command open the telnet port Report the system information close the system filewall
Step (IV) • try the rootkit if it works • Now you can do anything The Telnet daemon has been replaced Input the ID and the Password Which predefine by us We have got a root shell now
Summary • Checking the OS and applications’ vulnerability periodically. • Catch the idea of “Defense in Depth.”
Reference • CERT • http://www.cert.org/ • Nmap • http://incsecure.org/ • Buffer Overflow and RootKits download site • http://www.flatline.org.uk/~pete/ids/