Security Advisory WSO2-2020-0706

Published: May 13, 2020

Version: 1.0.0

Severity: High

CVSS Score: 8.7 (CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N)


  • WSO2 API Manager : 3.0.0
  • WSO2 IS as Key Manager : 5.9.0


API Manager bypass JWT signature verification for cached API requests.


A user can bypass the JWT signature verification and make a API request with any JWT claim value (with the previous signature), if the API is already invoked and the JWT signature is cached.


This vulnerability can lead to the exposure of API resources. Further, an attacker can do the unintended operations on API resources and harm.


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.