Security in the Cloud
Conventional infrastructure security controls designed for dedicated hardware do not always map well to the cloud
environment. Cloud architectures must have well-defied security policies and procedures in place. Realizing full
interoperability with existing dedicated security controls is unlikely; there has to be some degree of compatibility
between the newer security protections specifially designed for cloud environments and traditional security controls.
Integrated Cloud Security
Traditional environments segment physical servers with VLANs. Cloud environments should take this same approach
and segment virtual machines by VLANs through Port Group confiurations. Since these are physical servers, traff
flws are visible to traditional network-based security protection devices, such as network-based intrusion prevention
systems (IPSs). The concern in cloud environments is that IPS systems provide limited visibility to inter-virtual machine
traff flws. These are the flws between virtual machines on the same VLAN. By default, those traff flws are not
visible to traditional network-based security protection devices located in the datacenter network. Administrators must
make specifi architecture and confiuration decisions either to make the virtualization solution work with current
security tools or to integrate security appliances into the virtualization architecture.
IT teams can also leverage a virtual infrastructure aware IPS solution, integrated with the hypervisor, to provide the
needed visibility and security to prevent communication directly between hosted partitions within the virtual server.
These directly integrated solutions employ hypervisor-based APIs, and can also be used to ensure that even offle
virtual machines are protected and can stay up to date with patches, AV/IDS signatures fiters and rules while they are in
an offle or mobile state.
Cloud Burst Security
One of the primary advantages of cloud computing is that enterprises can move applications that consist of several
virtual machines to the cloud provider when the physical environment requires additional processor or compute
resources. These bursting virtual machines need security policies and baseline histories to move with them. When a
virtual machines moves, if the security policy does not accompany it, that virtual machines becomes vulnerable. In
addition, when virtual machines move, they lose their performance histories and administrators must re-evaluate the
virtual machine performance baselines.
Compliance Concerns
The auditing community is aware that current practices for auditing cloud environments are inadequate. As compliance grows in importance, enterprises implementing clouds need to satisfy their auditors’ concerns, especially since
creating an identity for an individual virtual machine and tracking that virtual machine from creation to deletion creates
challenges for even the most mature virtualized environments. Virtual machine sprawl-- when the number of virtual
machines being created is growing more quickly than an enterprise’s ability to manage them-- adds complexity.
Defense in Depth
Strategies for ensuring perimeter security have evolved signifiantly over the last few years. Today, most enterprises
have deployed layered defense strategies, but server virtualization can complicate matters. In an attempt to consolidate
servers, many organizations have left themselves vulnerable to the inter-virtual machine communications that exist,
because if one virtual machine is compromised, then all the other virtual machines that are part of the virtual network
can be compromised without anyone detecting it.
By providing security services from within the cloud provider infrastructure, enterprises are able to deploy security
policies and rules between each virtual machine (or between virtual machine centers) as they would in the physical
world. A feature of the cloud provider infrastructure is that enterprises can maintain corporate security policies and the
data collected about them with the virtual machines. This allows them to enforce security services in the enterprise and
the cloud provider consistently