Mattermost 6.3.0 and earlier fails to properly sanitize the HTML content in the email invitation sent to guest users, which allows registered users with special permissions to invite guest users to inject unescaped HTML content in the email invitations.
Solution:
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Link | Tags |
---|---|
https://mattermost.com/security-updates/ | release notes vendor advisory |
https://hackerone.com/reports/1443567 | third party advisory exploit |