Free Trial

Public Wi-Fi: Stealing Secrets in the Air

By Colm 31st January 2019

‘Free Wi-Fi’ – a phrase so commonly heard today that we have come to expect it in most public places. The vast majority of hotels, restaurants, coffee shops and transport systems today offer some form of Wi-Fi network for its guests and customers. In recent years, exploits using equipment such as the Wi-Fi Pineapple have captured the attention of IT Professionals and have raised awareness of the vulnerability of public Wi-Fi networks. However, in reality such attacks are rare. A much more significant issue is the ease with which anyone can quietly view unencrypted internet traffic transmitted on any network to which they can attach. But how exactly does this occur and how can it put Wi-Fi users and corporate data at risk?

Open Wi-Fi Networks

Most businesses and public places that offer free Wi-Fi do so with an open Wi-Fi network, allowing users to connect to an access point without the need for a password. Customers in the vicinity simply select the network they wish to use from the list detected by their device and connect. However, what most users are unaware of is how easy it is for anyone nearby to gain access to the traffic sent over this network. With basic IT skills and simple utilities, which are for example built into Macbooks, in the right location, anyone can sniff packets and perform a packet trace on a Wi-Fi network with unsecured traffic. This means that when using the network, both the content of the user’s unencrypted traffic, i.e. their searches, messages, usernames and passwords, and their browsing destination regardless of encryption, is made visible to the third party. This becomes dangerous when the content or destination of the user’s traffic is sensitive or confidential.

Closed Wi-Fi Networks

Unlike open networks, some public Wi-Fi connections do require a password to access the internet. However, despite their seemingly more secure systems, these too can be intercepted relatively easily. In reality, most public places that require a password to access their free Wi-Fi do not do so to provide extra security for the network but rather to limit access to paying customers only. Because of this, password protection actually does very little to prevent third parties attaching to closed networks and sniffing the same traffic that is visible on an open Wi-Fi network. Even when the hacker does not know the password due to the limitations of Wi-Fi, widely available tools such as Wifite or airodumping-ng can be used to connect to a router, capture packets, and decrypt the password. WAP2 passwords in particular, if poorly configured, can be ascertained relatively easily in this way allowing anyone to attach to a network once they are in close proximity to the AP. Once access is gained to the network, all unencrypted traffic passing through is then made visible to the hacker, including the websites visited and users’ login credentials.

Wired Network Connections

Wired networks provide some security for public internet access as, given the need for a physical connection, they are fundamentally more difficult to hack. Malicious actors need to find a cable point to plug into and presumably these are only available in particular physical locations making it harder to covertly hack or access a network. However, hacking wired networks is not impossible and once accessed, the same information can be made visible to an attacker as on an open wireless network.

What to do?

In a recent report, it was discovered that 44% of organizations’ mobile workers connect to a non-corporate owned network more than half the time that they are working. As well as this, in 2018 87% of workers admitted to potentially putting company data at risk by accessing email, bank accounts and financial information while using public Wi-Fi, highlighting the real danger currently facing organizations.

So what can they do to protect their sensitive data? In the case of public Wi-Fi the best protection is prevention. Employees need to be trained to avoid sending any sensitive information unencrypted over any network and to be aware that on any Wi-Fi or wired network, other than one to which access is controlled by themselves or an organization they trust, where they go online and any data accessed, received or sent can be made visible to anyone.


To find out more about Wi-Fi, the other risks facing mobile devices, and how Corrata Security and Control can help, visit or email us at

And for more industry news, insights and analysis – follow us on Twitter and LinkedIn!