CloudStack users can add and read comments (annotations) on resources they are authorised to access.  Due to an access validation issue that affects Apache CloudStack versions from 4.16.0, users who have access, prior access or knowledge of resource UUIDs can list and add comments (annotations) to such resources.  An attacker with a user-account and access or prior knowledge of resource UUIDs may exploit this issue to read contents of the comments (annotations) or add malicious comments (annotations) to such resources.  This may cause potential loss of confidentiality of CloudStack environments and resources if the comments (annotations) contain any privileged information. However, guessing or brute-forcing resource UUIDs are generally hard to impossible and access to listing or adding comments isn't same as access to CloudStack resources, making this issue of very low severity and general low impact. CloudStack admins may also disallow listAnnotations and addAnnotation API acces…

Account users in Apache CloudStack by default are allowed to upload and register templates for deploying instances and volumes for attaching them as data disks to their existing instances. Due to missing validation checks for KVM-compatible templates or volumes in CloudStack 4.0.0 through 4.18.2.3 and 4.19.0.0 through 4.19.1.1, an attacker that can upload or register templates and volumes, can use them to deploy malicious instances or attach uploaded volumes to their existing instances on KVM-based environments and exploit this to gain access to the host filesystems that could result in the compromise of resource integrity and confidentiality, data loss, denial of service, and availability of KVM-based infrastructure managed by CloudStack. Users are recommended to upgrade to Apache CloudStack 4.18.2.4 or 4.19.1.2, or later, which addresses this issue. Additionally, all user-uploaded or registered KVM-compatible templates and volumes can be scanned and checked that they are flat fi…

A problem has been identified in the CloudStack additional VM configuration (extraconfig) feature which can be misused by anyone who has privilege to deploy a VM instance or configure settings of an already deployed VM instance, to configure additional VM configuration even when the feature is not explicitly enabled by the administrator. In a KVM based CloudStack environment, an attacker can exploit this issue to attach host devices such as storage disks, and PCI and USB devices such as network adapters and GPUs, in a regular VM instance that can be further exploited to gain access to the underlying network and storage infrastructure resources, and access any VM instance disks on the local storage. Users are advised to upgrade to 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.