exploit

exploit : invalid input
exploit code : program to input invalid value
exploit-db.com : a web page which has many exploit codes

port scan

send TCP SYN packet
response SYN/ACK　→　open
response RST or no reaction　→　close

Get version information

/* Open SSH */
$ telnet 127.0.0.1 22
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
SSH-2.0-OpenSSH_6.0p1 Debian-3ubuntu1

/* Apache */
$telnet 127.0.0.1 80

nmap comand

sudo nmap -sSVC -0 127.0.0.1
-sS : SYN scan
-sV : Research service and version
-sC: Research detail info with service
　 Use custom script (LUA)
-O: Assume OS

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