The iPhone 911 Bug is a serious security issue that has been discovered in iOS 10. It is not a new flaw in design, but rather one that has reemerged. The bug can auto-dial numbers and lock the user out so that they cannot cancel the call. In 2008, a similar flaw in iOS Safari was triggered which tied up 911 call centers across the United States.
Apple patched the bug in Safari, but it has shown up again, this time in WebView. WebView is an application program interface (API) that allows developers to open web pages within their app rather than opening in an external browser. TechRadar cites the Twitter and LinkedIn apps as using the function, but several other apps use WebView as well. APIs are useful tools for including features in an application without having to program that feature by hand. Unfortunately, as such, it is sometimes difficult to know what bugs and glitches the API might cause.
Additionally, it can be difficult to tell when WebView has been invoked. It is challenging because Apple has tried to make the user interface as seamless as possible in iOS 10. By quietly opening web pages in Chrome or Safari, Apple has created the illusion that web pages are opening within the app, rather than in an external browser.