By default the CloudStack management server honours the x-forwarded-for HTTP header and logs it as the source IP of an API request. This could lead to authentication bypass and other operational problems should an attacker decide to spoof their IP address this way. Users are recommended to upgrade to CloudStack version 4.18.1.1 or 4.19.0.1, which fixes this issue.
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.