Security Advisory WSO2-2020-0699

Published: May 13, 2020

Version: 1.0.0

Severity: High

CVSS Score: 7.6 (CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L)


  • WSO2 IS as Key Manager : 5.9.0 or earlier
  • WSO2 Identity Server : 5.9.0 or earlier


A potential security vulnerability has been identified in the SMS OTP Authenticator.


When a SMS OTP Authentication is used, allows attackers to bypass SMS OTP Verification by sending a subset of backup codes.


Successful exploitation of this vulnerability allows an attacker to bypass the second-factor authentication mechanisms and gain unauthorized access to the application.


If you are using an affected product version, it is highly recommended to migrate to the latest released version to receive security fixes.

Otherwise, you may apply the relevant fixes to the product based on the public fix(s):


If you are a WSO2 customer with a support subscription, use WSO2 Update Manager(WUM) updates in order to apply the fix to the affected versions.