Security Advisory WSO2-2020-1139

Published: February 08, 2021

Version: 1.0.0

Severity: Medium

CVSS Score: 4.7 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N)


  • WSO2 API Manager : 2.6.0 , 3.0.0 , 3.1.0 , 3.2.0
  • WSO2 API Manager Analytics : 2.6.0
  • WSO2 IoT Server : 3.3.1


HTTP request headers get reflected in the response to the client.


When an HTTP based API request returns an error or when an HTTP OPTIONS call is made, request headers are returning back to the client as response headers, without any filtration from the server.


By leveraging this vulnerability, a malicious actor could set response header values in a way that might harm an unsuspecting user.


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.