OpenCTI is an open-source cyber threat intelligence platform. In versions starting from 6.4.8 to before 6.4.10, the allow/deny lists can be bypassed, allowing a user to change attributes that are intended to be unmodifiable by the user. It is possible to toggle the "external" flag on/off and change the own token value for a user. It is also possible to edit attributes that are not in the allow list, such as "otp_qr" and "otp_activated". If external users exist in the OpenCTI setup and the information about these users identities is sensitive, the above vulnerabilities can be used to enumerate existing user accounts as a standard low privileged user. This issue has been patched in version 6.4.10.