August 19, 2013

Why come inside, if I can stand out front?

A busines’ wireless access points offer the potential as a simple vector for network ingress by an attacker. They don’t require specific vulnerabilities, physical access or end user engagement.

All that is required is poor security configuration - either via the employed encryption standard or associated passwords.

The 3 broad access control mechanisms utilised today are:

What follows is a general wireless analysis of Sydney’s George Street.

1,514 total unique access points were discovered:

None 187
WEP 65
WPA 1,262

While the open access points need to be taken with a grain of salt (often intentionally open and guest networks), there is a subtle security concern associated with these networks - if your business blocks access to certain sites, a user can trivially bypass this control by connecting to an open network, downloading a potentially (or forced via man in the middle) harmful file and then reconnecting to the corporate network - introducing blocked resources into the environment.

Similarly WEP (particularly) or WPA can introduce a false sense of security at your corporate perimeter, where a WEP or WPA key can be cracked, guessed or read (yes, we can all seen the yellow post-it notes) - unpatched internal systems can be used as pivots to further explore your network and systems.

The most active access points (based on active connections) were:

Rank Encryption Total
1 WPA 31
2 WPA 23
3 None 23
4 None 22
5 None 20
6 None 19
7 None 19
8 None 18
9 None 18
10 None 17

The distribution of WPA protected access points (with names intentionally removed) can be seen below (similar diagrams for WEP and open networks will not be published):

/assets/images/wpa1.jpg

This analysis has shown that while 83% of access points are protected by strong access control mechanisms, some 17% are still utilising legacy or no protection - which while insecure in themselves, can also introduce vulnerabilities into your network by geographical association.