Knowage Access Control Bypass
Release date: 29/07/2019
Last update: 29/07/2019
Vendor site: https://www.knowage-suite.com/site/home/
Affected version(s): 6.1.1
Remediated version: 6.4
Severity Rating: High
Impact: Exposure of sensitive information
Attack vector: Remote without authentication
Details: It is possible to perform administrator functions without being authenticated. The parameter “user_id” needs to be added to each request and it must contain a valid administrator username. Guessing a valid username is trivial, as it is usually called “biadmin”, “admin” or “administrator”.
The following link provides a proof of concept:
The following screenshot shows the result of the proof of concept, which displays all current users and their password hash from the application.
It is possible to use this vulnerability to perform any administrator function in the application, which includes adding another administrator user to the application and then logging on as that new user.
The following shows a screenshot of adding a new administrator user to the system:
The sbiExtUserRoleses attribute uses an id for each access group, in this instance, this applies all access groups to the user.
This vulnerability allows for an unauthenticated user to obtain application administrator access.
Recommendation: Update to the latest patch.
Discovered by: David Chadwick from Content Security Pty. Ltd.