Xen Project discloses serious vulnerability that impacts virtualized servers

Major cloud providers like Amazon and Rackspace were forced to reboot some of their servers in order to apply the patch

The Xen Project has revealed the details of a serious vulnerability in the Xen hypervisor that could put the security of many virtualized servers at risk.

Xen is a free, open-source hypervisor used to create and run virtual machines. It is widely used by cloud computing providers and virtual private server hosting companies.

The security vulnerability, which is being tracked as CVE-2014-7188 and was privately disclosed to major cloud providers in advance, forced at least Amazon Web Services and Rackspace to reboot some of their customers' virtualized servers over the past week.

The issue allows a virtual machine created using Xen's hardware-assisted virtualization (HVM) to read data stored by other HVM guests that share the same physical hardware. This breaks an important security barrier in multi-tenant virtual environments.

A malicious HVM guest can also exploit the flaw to crash the host server, the Xen Project said in a security advisory published Wednesday.

The vulnerability only affects Xen running on x86 systems, not ARM, and does not impact servers virtualized with Xen's paravirtualization (PV) mode instead of HVM.

Even so, the issue is likely to affect a very large number of servers. Amazon was forced to reboot up to 10 percent of its Elastic Cloud Compute (EC2) servers over the last several days in order to apply the patch and Rackspace's similar effort affected a quarter of its 200,000 customers.

Amazon scheduled its reboots so they didn't affect two regions or availability zones at the same time.

"The zone by zone reboots were completed as planned and we worked very closely with our customers to ensure that the reboots went smoothly for them," the company said Wednesday in a blog post.

Things did not went as smooth for Rackspace whose CEO, Taylor Rhodes, admitted in an email sent to customers Tuesday that the company "dropped a few balls" in the process of dealing with the vulnerability.

"Some of our reboots, for example, took much longer than they should," Rhodes said. "And some of our notifications were not as clear as they should have been. We are making changes to address those mistakes."

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags patch managementvirtualizationServer VirtualizationAmazon Web ServicesrackspacepatchesExploits / vulnerabilities

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.
Lucian Constantin

Lucian Constantin

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers

MSI P65

This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang

MSI GT76

It really doesn’t get more “gaming laptop” than this.

Jack Jeffries

MSI GS75

As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr

MSI PS63

The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?