CVE-2022-31107

Grafana is an open-source platform for monitoring and observability. In
versions 5.3 until 9.0.3, 8.5.9, 8.4.10, and 8.3.10, it is possible for a
malicious user who has authorization to log into a Grafana instance via a
configured OAuth IdP which provides a login name to take over the account
of another user in that Grafana instance. This can occur when the malicious
user is authorized to log in to Grafana via OAuth, the malicious user’s
external user id is not already associated with an account in Grafana, the
malicious user’s email address is not already associated with an account in
Grafana, and the malicious user knows the Grafana username of the target
user. If these conditions are met, the malicious user can set their
username in the OAuth provider to that of the target user, then go through
the OAuth flow to log in to Grafana. Due to the way that external and
internal user accounts are linked together during login, if the conditions
above are all met then the malicious user will be able to log in to the
target user’s Grafana account. Versions 9.0.3, 8.5.9, 8.4.10, and 8.3.10
contain a patch for this issue. As a workaround, concerned users can
disable OAuth login to their Grafana instance, or ensure that all users
authorized to log in via OAuth have a corresponding user account in Grafana
linked to their email address.