Security Advisory WSO2-2021-1347

Published: September 02, 2021

Version: 1.0.0

Severity: High

CVSS Score: 8.3 (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H)


  • API Microgateway Toolkit Linux : 3.2.0
  • API Microgateway Toolkit Mac : 3.2.0
  • API Microgateway Toolkit Windows : 3.2.0


An improper certification validation vulnerability leading to possible malicious code execution.


Due to an improper certification validation a malicious actor could perform a person-in-the-middle attack by manipulating Ballerina dependencies when retrieving such from the Ballerina Central. This retrieval happens when building the microgateway using the micro-gw build command.


In order for the attack to succeed, an malicious actor should be able to perform a person-in-the-middle attack on the TLS connection, and alter response traffic relevant to the communication in between the host executing 'micro-gw build' command and the Ballerina Central. By leveraging the vulnerability, a malicious actor may perform an Remote Code Execution by injecting a malicious code into the system.


If the latest version of the affected WSO2 product is not mentioned under the affected product list, you may migrate to the latest 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 Updates in order to apply the fix.


WSO2 thanks, Simon Gerst for responsibly reporting the identified issue and working with us as we addressed it.