On August 9 an internal security review identified a vulnerability
in the Grafana which allows an escalation from Admin privileges
to Server Admin when Auth proxy authentication is used.
Auth proxy allows to authenticate a user by only providing the username
(or email) in a X-WEBAUTH-USER HTTP header: the trust assumption
is that a front proxy will take care of authentication and that Grafana server
is publicly reachable only with this front proxy.
Datasource proxy breaks this assumption:
- it is possible to configure a fake datasource pointing to a localhost
Grafana install with a
X-WEBAUTH-USER HTTP header containing
admin username.
- This fake datasource can be called publicly via this proxying feature.
The CVSS score for this vulnerability is 6.6 Moderate
(CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H).