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.
The CloudStack management server and secondary storage VM could be tricked into making requests to restricted or random resources by means of following 301 HTTP redirects presented by external servers when downloading templates or ISOs. Users are recommended to upgrade to version 4.18.1.1 or 4.19.0.1, which fixes this issue.