Securing Hyper-V 2012R2 hosts and VMs
Microsoft has implemented a lot of new cool security features in Hyper-V on the 2012R2 release, and most importently statefull firewall and network inspection features.
From the 2012 release, Microsoft introduced features like
* ARP Guard https://msandbu.wordpress.com/2013/04/03/arp-guard-in-hyper-v-2012/
* DHCP Guard
* Router Guard
(These three functions are also included in regular network devices from most vendors)
The use of Bandwidth control as well is useful for limiting for instance DDOS attacks.
* Bitlocker with Network Unlock (To protect a VM from theft)
* NVGRE (Network virtualization, which is not a security feature but it can be used to define each customer to its own network segment without the use of VLANs (This offers security since it is not able for instance to use VLAN-hopping)
* PVLAN (In many cases the use of VLANS still has its purpose for instance you can define three types of PVLANs (Isolated, Promiscuous and Community)
* VM stateless firewalls (Not on the indvidual VM but on the Hyper-V traffic going to the VMs) But these had pretty limited functionality (Which was restricted to IP-ACL, couldn’t define port or TCP EST)
* Bitlocker for CSV (Encrypt everything in a cluster)
So what else has Microsoft implemented of Security mechanisms in the OS-stack with the new R2 release ?
Not much info here yet.. but they are mostly related to hyper-v networking rules, new generation VMs with UEFI boot options (UEFI enable secure boot which makes it harder for rootkits to get installed)
What else can you do to secure your hosts and VM*s running on Hyper-V?
Microsoft has released a built-in baseline configuration that you can start from Server Manager this has some rules that It can use to scan if your hosts are according to best-practice, this offers you tips on what you should do.
Microsoft also offers other tools that can be used deploy security according to best practice (This uses Group Policy for deployment of security settings) for instance Security Compliance Manager http://www.microsoft.com/en-us/download/details.aspx?displayLang=en&id=16776
Installing all Hyper-v hosts as Server Core will also limit the attack surface on the hosts since it does not install all the unnecessery components like Internet explorer, .Net framework etc.
Which makes the host less open for attacks. (And also don’t use RDP there have been many security holes here which hackers have taken advantage of so If you need to enable RDP use NLA as well)
Monitoring / Antivirus and Patching
Integration with System Center also can prove to be quite useful for many reasons.
Which can offer you features like
* Anti-malware / Anti-virus (Configuration Manager)
* Patch management (Virtual Machine Manager / Configuration Manager)
* Baselining and remediation (Configuration Manager / Virtual Machine Manager)
* Monitoring (Operations Manager)
But this will require a number of agents being installed on all VM’s for instance Configuration Manager with Endpoint Protection and Operations Manager (and VMM agent on Hyper-v hosts)
(NOTE: You can enable baseline configuration in Operations Manager as well, instead of using Server Manager and with the integration of System Center Advisor you will get more intel)
Now Microsoft recommends that the parent partition to be as clean as possible, therefore they recommend not installing AV on the Hyper-V hosts (Since you will also suffer some performance loss), but if it is a part of the company policy.
Remember that if you install endpoint protection for Hyper-V hosts, put exclusions for these folders.“%PROGRAMDATA%\Microsoft\Windows\Hyper-V”
You can read more about it here –> http://social.technet.microsoft.com/wiki/contents/articles/2179.hyper-v-anti-virus-exclusions-for-hyper-v-hosts.aspx
When regarding firewalls, each host running Windows has Windows Firewall enabled by default, should we then use Hyper-V port ACLs also ?
Hyper-V port ACLs follow the virtual machines so if you move them to another host, the ACL sticks. But they have different features.
The built-in firewall from Windows can allow Applications to communicate and is not restricted to a port or protcol, the firewall can also use IPsec.
While a Hyper-V port ACL can check if it is a statefull connection while the built-in firewall cannot. Hyper-V port ACL can also measure the traffic bandwidth that goes trough.
For many reasons you should use for built-in firewall for most cases (Create Group policies for the most common use server roles) and in more extreme cases where you need to lock down more and controll the traffic flow more you deploy and hyper-v port ACL.
You should also move your management traffic to a dedicated NIC outside of other traffic so it is not so easy to “sniff” on your traffic.
RBAC (Role Based Access Control) an easy rule of thumb is to split user rights where you can.
For instance an hyper-v administrator should not have admin-rights on VMs and vice versa.
If you are using SCVMM you should create custom User Roles (For instance you can define a user role that (Group 1) has access to which can be used to administrate their hosts (Which is under a host group) and access to certain run as roles)
Sysinternals also should be used when evaluating your security for instance to see if there are any open ports that shouldn’t be open by using TCPView
Make sure that your internal network is configured as it should.
By disabling CDP on access ports (If you are using Cisco)
Enabling all ports as Access Ports (Portfast) so you can’t be hijacked by STP attacks.
http://www.microsoft.com/en-us/download/details.aspx?id=16650 This is an old security guide from Microsoft but alot of it still applies today.
Might also mention that there are some third party solutions that you can use to secure Hyper-V.
Posted on august 1, 2013, in Uncategorized and tagged arp guard, Hyper-v, nvgre., router guard, security, statefull firewalls, watchguard, windows server 2012 r2. Bookmark the permalink. Legg igjen en kommentar.