Apple Rushes Fix for Latest ‘Text Bomb’ Bug As Abuse Spreads

Apple said it is working on a fix for the latest text bomb bug that crashes a number of iOS and Mac apps that display specific Telugu language characters.   


Apple said it is working on a fix for the latest text bomb bug that crashes a number of iOS and Mac apps that display specific Telugu language characters. On Monday, it made good on the promise and announced the availability of a patch (CVE-2018-4124) for iOS 11.2.6, watchOS 4.2.3, tvOS 11.2.6, and macOS 10.13.3 that addresses the flaw.

The bug, first reported by Italian Blog Mobile World, impacts a wide range of Apple apps running on iOS and macOS. While some iPhone users are reporting system crashes, others are reporting cases where the specially crafted message disables access to Apple’s iMessage and other apps such as WhatsApp, Facebook Messenger, Outlook and Gmail running on the latest version of Apple’s operating system (iOS 11.2.5).

Last week, Apple declined to comment, however confirmed to Threatpost a fix would be available soon and that publicly available beta versions of iOS, tvOS, macOS and watchOS are not impacted by the bug.

In a very brief technical description of the bug, posted by Apple on Monday, it said  the flaw occurred when affected Apple products processed a maliciously crafted string that could lead to a heap corruption. “A memory corruption issue was addressed through improved input validation,” according to the Apple advisory announcing its mitigation efforts.

This most recent text bomb bug is triggered when someone sends two Unicode symbols using the Indian language (Telugu) characters to iOS and macOS apps using Apple’s default San Francisco font. When the message is received Apple’s home screen manager called Springboard hiccups resulting in apps freezing. In other reported instances devices crash and require a restart. In many cases, users can’t reopen affected apps and are forced to delete and reinstall the affected application.

Knowledge of the bug has motivated a wide range of malicious or prank attacks on Twitter. According reports, not only are some sending Telugu text bomb’s as private messages, but also using social media platforms such as Twitter.

“A Twitter user with the symbol in their screenname ‘liked’ one of my tweets late on Thursday night. Shortly after the notification popped into my feed, my Twitter app on iOS became briefly unresponsive before crashing,” described Motherboard contributor Joseph Cox in post Thursday.

In addition, Cox pointed out a post by security researcher Darren Martyn that showed how people could crash Apple’s networking application simply by putting the symbol in the name to the Wi-Fi network.

Apple is no stranger to text bombs. In January, Apple dealt with a similar iOS headache tied to a specific URL. In that case, when the URL (iabem97[.]github[.]io/chaiOS/) was sent to the iPhone, iPad or Mac’s Messages app it brought it to a grinding halt. In 2016, another malicious URL crashed iPhones and the Safari browser.

The flaw was reported to Open Radar, an Apple community bug reporting site, on Monday. According to the report, impacted Apple operating systems include iOS, MacOS and watchOS.

(This article was updated on 2/20/2018 to reflect a patch available to fix the problem.)

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