** DISPUTED ** Cross-site scripting (XSS) vulnerability in the Facebook app 14.0 and the Facebook Messenger app 10.0 for iOS allows remote attackers to inject arbitrary web script or HTML via a crafted filename extension that is improperly handled during MIME sniffing of chat traffic.  NOTE: the vendor disputes the significance of this report, because the user must accept an interstitial warning before the HTML file content is rendered, and because the HTML content's origin is a sandbox domain.