Archive for the 'XenServer' Category

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DEF CON 24 DEMO: Double Tagging VLAN Hopping Attack Between Two Virtual Networks With a Cisco 2950 Switch in the Middle

This post demonstrates the effects of using a double tagging vlan hopping attack to send an ICMP packet from a virtual machine located in one hypervisor environment to another virtual machine located in a separate hypervisor environment connected to the same physical switch. In this scenario the attacker is using a virtual Kali 2.0 system located within the Citrix XenServer hypervisor environment and targeting a virtual machine located on a separate VLAN within the ProxMox hypervisor environment.

This experiment was performed on seven different hypervisor/virtual network configurations in order to perform a systematic evaluation of the effects across all of the major enterprise level virtualization platforms. The following network diagram illustrates the configuration used for each of the experiments:

double_tagging_virtual

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DefCon 23 Presentation: Exploring Layer 2 Network Security in Virtualized Environments

DefCon 23 Video Demo: Rogue DHCP/DNS server gaining root access to target

DefCon 23 Video Demo: Rogue DHCP/DNS server ShellShock exploit proof of concept

DefCon 23 Video Demo: Rogue DHCP/DNS server on Citrix XenServer 6.2 with Open vSwitch 1.4.6

DefCon 23 Video Demo: MAC Flooding on Citrix XenServer 6.2 with Open vSwitch 1.4.6

Exploring Layer 2 Network Security In Virtualized Environments – DerbyCon 4.0

I gave a talk this past weekend on part of my Ph.D. dissertation research at the DerbyCon 4.0 “Family Rootz” Computer Security conference in Louisville, KY. Take a look at the following video to view the talk in its entirety. The rest of the conference videos are available here.

 

 

Xen Cloud Platform (XCP) – Cloning Hard Drive Woes

The main hard drive seems to be flaky in one of my XCP servers. I decided to use Clonezilla to clone sda to another drive to see if it is in fact the hard drive. After cloning over the drive I found that my LVM storage group VG_XenStorage-xxx was not mounting, and XenCenter was giving off the following error when trying to connect to the server: “This server cannot see any storage”

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Xen Cloud Platform (XCP) – Assigning A VLAN An IP Address

Once you create VLAN’s on your XCP server you will find that the physical interface you used to be able to hit by an IP address no longer responds. This is because you have trunked the interface into multiple VLAN’s and need to assign IP’s to the VLAN interfaces rather than the physical interface.

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Xen Cloud Platform (XCP) – Setting Up A VLAN

One very useful feature of XCP is the ability to setup VLAN networks for your virtual machines to use. This gives an administrator fine grained control on what network a machine belongs on. This will work as long as the network interface that is assigned to your VM’s is plugged into a trunked port on a switch that has been setup with VLAN tags.

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