A vulnerability in the Steam gaming platform enabled account hijacking through its password reset mechanism. Kotaku, a popular blog among gamers, said a number of prominent Steam accounts and Twitch streamers were stolen or accessed remotely. The flaw was reportedly patched during the weekend, according to reports. Steam does offer a two-factor authentication mechanism called Steam Guard, which adds a mobile number to a Steam member s account through which a Steam Guard code is sent to the user to be used as a second form of authentication.
Source: https://threatpost.com/valve-patches-password-reset-vulnerability-in-steam/113976/