Canonical has published details in a security notice about a WPA and WPA2 vulnerability that has been found and fixed in Ubuntu 15.04, Ubuntu 14.10, Ubuntu 14.04 LTS, Ubuntu 12.04 LTS, and Ubuntu 10.04 LTS operating systems.
The developers who fixed the issue explained that wpa_supplicant and hostapd could have been made to crash if they received specially crafted network traffic. Ubuntu maintainers have been quick.
According to the security notice, "Kostya Kortchinsky discovered multiple flaws in wpa_supplicant and hostapd. A remote attacker could use these issues to cause wpa_supplicant or hostapd to crash, resulting in a denial of service. (CVE-2015-4141, CVE-2015-4142, CVE-2015-4143, CVE-2015-4144, CVE-2015-4145, CVE-2015-4146)."
For a more detailed description of the problems, you can see Canonical's security notification. Users should upgrade their Linux distribution in order to correct this issue.
The flaw can be fixed if you upgrade your system(s) to the latest hostapd and wpasupplicant packages specific to each distribution. To apply the patch, users can simply run the Update Manager application.
If you don't want to use the Software Updater, you can open a terminal and enter the following commands (you will need to be root):
sudo apt-get dist-upgrade