Improper access control in the TeamViewer Full and Host clients (Windows, macOS, Linux) prior version 15.74.5 allows an authenticated user to bypass additional access controls with “Allow after confirmation” configuration in a remote session. An exploit could result in unauthorized access prior to local confirmation. The user needs to be authenticated for the remote session via ID/password, Session Link, or Easy Access as a prerequisite to exploit this vulnerability.
If an immediate update of the client is not possible and the use of additional access controls is required, the access control setting “Control this computer – Allow after Confirmation” can be set as mitigation. This prevents exploitation. The access controls can be configured in the Client Settings – “Advanced Options > Advanced Settings for connections to this computer” or via Policies “Access Control (incoming connections)”.
Update to the latest client version (15.74.5 or the latest version available).