The KRACK WIFI vulnerability was announced by security researchers and the US-CERT today. This vulnerability can affect every modern WIFI network and has the potential to impact every device that connects to WIFI. If affected, KRACK could allow for any information sent over wifi to be stolen including passwords, credit card numbers, private emails, and so on. This vulnerability is a major problem for our enterprises and users. Vendors will be required to step up and provide fixes quickly and everyone throughout the organization to pitch in and follow the recommended remediation.
What is KRACK?
KRACK is a vulnerability in the most common security protocol, WPA2, used to authenticate WIFI connections to a secure network and is used by virtually every WIFI network. When this vulnerability is exploited, it permits an attacker to decrypt the session between a WIFI client (e.g. a mobile device) and the server (e.g. wireless router). In certain cases, it would permit the alteration of content. All versions of WPA2 are affected.
How serious is it for me?
KRACK is a very serious problem in the long run, but how concerned you should be in the short term depends upon analyzing your threats. Threats of concern are those that are local (e.g. within range of your WIFI) and interested in compromising the confidentiality or integrity of your trusted network and the data it contains. This means that it is not scalable to international actors such as crime cartels. It can only be exploited by a local actor.
What actions should I be taking?
In the short term, we suggest revisiting your threat assessment and your staff training. To assess if the threat is imminent, determine whether a local person (e.g.. disgruntled current or former staff) who may be interested and capable of exploiting this vulnerability. If this threat exists, a defensive strategy should be developed.
The specific strategy is very organization specific but should include working with law enforcement, upgrading monitoring and log analysis, changing of firewall rules or restructuring of trust zones. Staff should also be trained to pay close attention to HTTPS connections. This protocol is a weak protection against exploitation, but if the user always checks the internal web resource is protected (e.g. lock icon or “https://” in the URL) the contents will still be encrypted as a second line of defense. Users must be trained to pay attention to this as they may not receive alerts if it is missing.
Long-term, we recommend that you connect with all vendors of WIFI associated equipment that is used in your environment and determine their schedule for release of software patches and upgrades. As soon as these are available, install and test each wireless device to ensure proper function.
What WIFI connections and activities are safe?
Bear in mind that “Safe” is a relative word in cybersecurity. These are safer activities,
- Use of SSL (HTTPS) connections encrypt data, but the user must pay close attention; and
- Use of “Thinclients” (e.g. Citrix, VNC or other proprietary protocols) which allow connection to a data that is a picture of the data, rather than a copy of the data.
What WIFI connections are unsafe?
The following connections are not considered safe,
- VPN connection assumed to be trusted and not using SSL (HTTPS);
- Internal wireless connection where internal servers do not require SSL;
- Home WIFI of remote users;
- Anywhere that the login credentials to WIFI can be reused in another context (e.g. Active Directory);
- Wherever WPA2 is used in any form to connect to a wireless access point.
To summarize, a new vulnerability has just come to light that impacts WIFI connections. This vulnerability can only be carried out by a local actor, therefore you need to evaluate potential threats to staff and others. If you determine an imminent threat, you should take action immediately. Otherwise, install and test updates from WIFI associated equipment vendors to mitigate this vulnerability.
For up-to-date information about the patches you need to secure your wifi, please visit ZD Net.