Preface: One of the objective for Aggregation Services aim to provision and manage a huge number of separate physical platforms. As a result, the international vendor like Cisco also doing the transformation of the physical network devices. And therefore we seen VM devices OS system image today.
Synopsis: In order to cope with cloud computing and container environment, IOS XR 64-bit operating system (OS) is able to runs on virtualized environment with underlying 64-bit Linux kernel. As a result, the cisco product services can be extended.
A vulnerability in the sysadmin virtual machine (VM) on Cisco ASR 9000 Series Aggregation Services Routers running Cisco IOS XR 64-bit Software could allow an unauthenticated, remote attacker to access internal applications running on the sysadmin VM.
Official remedy solution: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-asr9k-exr