Xen Hypervisor Security Issue

A new security problem in Xen hypervisor which force the AWS cloud and Rackspace, to restart the server in the cloud, for the second time in five months.Is according to a report from GigaOM, AWS customers told in a premium support bulletin that 10% of instances are affected on March 10 of all cases of EC2.
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“We built the capacity to live-update the vast majority of our fleet;. However, we have not allowed this capacity in some of our old hardware This old hardware is what resets” AWS said.

Rackspace said the update requires critical maintenance, affecting some of its servers first and the next generation of cloud. Your On Metal Cloud Servers are not affected.

“Although we make every effort to minimize service interruptions, the security of your environment is our top priority,” he said in a post Rackspace community. “We understand that any impact of downtime for your business and you do not make this decision lightly. In preparation for the potential restart, we recommend you take proactive steps to secure your environment is set to return to the appropriate operations.”

Both providers are staggering reboot as cases in different regions will not restart at the same time.

In September, both AWS and Rackspace had to restart parts of the clouds because of a security vulnerability that affects some versions of XenServer. While there were no reports of compromised data, the vulnerability could have allowed people with bad intentions to read data fragments that belong to others or host server to crash through following a specific set of commands by heart.