Citrix XenServer 7.1 and newer allows Directory Traversal.

A heap buffer overflow flaw was found in QEMU's Cirrus CLGD 54xx VGA emulator's VNC display driver support before 2.9; the issue could occur when a VNC client attempted to update its display after a VGA operation is performed by a guest. A privileged user/process inside a guest could use this flaw to crash the QEMU process or, potentially, execute arbitrary code on the host with privileges of the QEMU process.

Dell EMC iDRAC Service Module for all supported Linux and XenServer versions v3.0.1, v3.0.2, v3.1.0, v3.2.0, when started, changes the default file permission of the hosts file of the host operating system (/etc/hosts) to world writable. A malicious low privileged operating system user or process could modify the host file and potentially redirect traffic from the intended destination to sites hosting malicious or unwanted content.