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Applying a “Defense-in-Depth” Strategy

Monday, May 22, 2017 - Posted by Keith A. Smith, in Network, VMware, Microsoft, Linux, Security

IT Teams and Staff can effectively maintain physical and information security with a “defense-in-depth” approach that addresses both internal and external threats. Defense-in-depth is based on the idea that any one point of protection may, and probably will, be defeated. This approach uses three different types of layers (physical, electronic, and procedural) and applies appropriate controls to address different risks that might arise in each.
 
The same concept works for both physical and network security. Multiple layers of network security can protect networked assets, data and end points, just as multiple layers of physical security can protect high-value physical assets. With a defense-in-depth approach:  

System security is purposely designed into the infrastructure from the beginning. Attackers are faced with multiple hurdles to overcome if they want to successfully break through or bypass the entire system. 
A weakness or flaw in one layer can be protected by strength, capabilities or new variable introduced through other security layers. 

Typical defense-in-depth approaches involve six areas: physical, network, computer, application, device and staff education.

1. Physical Security – It seems obvious that physical security would be an important layer in a defense-in-depth strategy, but don’t take it for granted. Guards, gates, locks, port block-outs, and key cards all help keep people away from systems that shouldn’t touch or alter. In addition, the lines between the physical security systems and information systems are blurring as physical access can be tied to information access. 

2. Network Security – An essential part of information fabric is network security and should be equipped with firewalls, intrusion detection and prevention systems (IDS/IPS), and general networking equipment such as switches and routers configured with their security features enabled. Zones establish domains of trust for security access and smaller virtual local area networks (VLANs) to shape and manage network traffic. A demilitarized zone between public resources and the internal or trusted resources allows data and services to be shared securely. 

3. Computer Hardening – Well known (and published) software vulnerabilities are the number one way that intruders gain access to automation systems. Examples of Computer Hardening include the use of: 
Antivirus software
Application whitelisting
Host intrusion-detection systems (HIDS) and other endpoint security solutions
Removal of unused applications, protocols and services
Closing unnecessary ports

Software patching practices can work in concert with these hardening techniques to help further address computer risks that are susceptible to malware cyber risks including viruses and Trojans etc.

Follow these guidelines to help reduce risk:
Disable software automatic updating services on PCs
Inventory target computers for applications, and software versions and revisions
Subscribe to and monitor vendor patch qualification services for patch compatibility
Obtain product patches and software upgrades directly from the vendor
Pre-test all patches on non-operational, non-mission critical systems
Schedule the application of patches and upgrades and plan for contingencies 

4. Application Security  – This refers infusing system applications with good security practices, such as a Role Based Access Control System,Multi-factor authentication (MFA) also known as (also known as 2FA) where ever possible which locks down access to critical process functions, force username/password logins, combinations, Multi-factor authentication (MFA) also known as (also known as 2FA) where ever possible and etc. 

5. Device Hardening – Changing the default configuration of an embedded device out-of-the-box can make it more secure. The default security settings of PLCs, PACs, routers, switches, firewalls and other embedded devices will differ based on class and type, which subsequently changes the amount of work required to harden a particular device. But remember, a chain is only as strong as its weakest link. 

6. Staff Education - Last but not least it’s important to talk to staff about keeping clean machine, the organization should have clear rules for what employees can install and keep on their work computers.  Make sure they understand and abide by these rules. Following good password practices is important a strong password is a phrase that is at least 12 characters long. Employees should be encouraged to keep an eye out and say something if they notice strange happenings on their computer.  


Educating Employees at least once a year is important
Training employees is a critical element of security. They need to understand the value of protecting customer and colleague information and their role in keeping it safe. They also need a basic grounding in other risks and how to make good judgments online.

Most importantly, they need to know the policies and practices you expect them to follow in the workplace regarding Internet safety.


-End

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system_thread_exception_not_handled xen.sys BSOD

Friday, September 04, 2015 - Posted by Keith A. Smith, in VMware, Xen, Microsoft, Linux

The system_thread_exception_not_handled xen.sys BSOD issue was interesting to me;


I wanted to see if I could reproduce this. I exported a VM from Amazon's EC2 because Amazon EC2 uses the Xen hypervisor as well. I upload the VM into a datastore on vSphere and convert the virutal disk as I noted here http://bit.ly/1UrCpqN I power on the VM and I get the same system_thread_exception_not_handled xen.sys BSOD. I boot into safe mode I run a msconfig from the search, Under the boot tab I chose base video because I still had the xentools installed on the VM's. So that had to be the culprit right? I reboot the VM, and it boots fine, at this point I uninstall all the XenServer/Citrix related items. I then restart the VM and I was glad to see it make it to the login screen.

Solution: I think...Ermm
The way to avoid this issue if you are going from Xen to VMware or any other hypervisor is to uninstall all the XenServer/Citrix items before performing the export of the VM.
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Enable SSH login with Root

Friday, September 04, 2015 - Posted by Keith A. Smith, in Linux

I recently had a need to ssh into a *nix box using the root credentials for a particular situation. It took me a few minutes to figure out the following
  1. Open up /etc/ssh/sshd_config and set “PermitRootLogin” to “yes”. (Mine was set to “without-password”)
  2. I then restarted the sshd process. This is done by killing the existing one (use ps -aux|grep sshd to get the process ID, then use kill to zap it), then restarting /usr/sbin/sshd

Once I was done I did the above steps again but changing the "PermitRootLogin" to "without-password"
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