We have a few older HP laptops that when docked in a port replicator the WLAN connection is disabled and the LAN connection is enabled. We have since replaced these with Toshiba R700s which do not have this feature.
Is there any security risk in running both a WLAN and wired LAN connection at the same time?
Toshiba R700s are running Windows 7 Enterprise.
There is no specific security risk to having two network interfaces enabled, beyond the fact that it is possible for the user to not notice which interface is in use (e.g. the laptop may have automatically connected to a wireless network while the user thought it was using the ethernet connection). You can avoid this problem entirely by simply turning the wireless power switch off when using an ethernet connection, or just looking at your network status occasionally.
There is a theoretical risk, or you would not be asking. The reality is that if you have not disabled, or significantly changed, the Windows firewall you are pretty safe. In addition, you need to keep your computers patched (Windows Update and browser plugins up-to-date http://www.mozilla.com/en-US/plugincheck/ ...works for most browsers), and protected with anti-virus.
Most attacks happen from the inside, because you have not properly maintained your computer, and you get a virus.
The only security risk is that wireless can be hacked from outside of your office.
A (very) knowledgeable hacker can always get into a wireless network, bypassing all and any protections.
If this is a problem, wireless routers should not be allowed where the office external walls are within their possible range, or should only be used with a VPN.
The problem I see is when your wired and wireless networks are using different internet connections (separate routers or firewalls). For instance you may be connected to your corporate wired network at your office which also hosts a wireless network for guests on a separate internet connection. Most likely if this is the case then the security would be far lower on the wrls guest connection. Being connected to both of these networks at the same time would introduce a security risk to your corporate wired network because you have now effectively used your laptop as a bridge between the wired and wireless, meaning if someone gains access to your laptop via the wrls guest connection they would also have access to any resources you have access to on the wired. So my rule of thumb is to remember that you are connecting both networks together when you do this and therefore your network is only as secure as the weakest connection.
