"The weaknesses reside in Stagefright, a media playback tool in Android. They are all "remote code execution" bugs, allowing malicious hackers to infiltrate devices and exfiltrate private data. All attackers would need to send out exploits would be mobile phone numbers, Drake noted. From there, they could send an exploit packaged in a Stagefright multimedia message (MMS), which would let them write code to the device and steal data from sections of the phone that can be reached with Stagefright's permissions. That would allow for recording of audio and video, and snooping on photos stored in SD cards. Bluetooth would also be hackable via Stagefright."
This makes me a little paranoid, which leads to my first question: How accurate are carriers' own internal tools for measuring use, and do you recommend any third-party apps for keeping track of data use? Ideally, I'd like a detailed breakdown by app, over time: I don't think I'm at risk for data-stealing malware on my phone (the apps I use are either built-in, or plain-vanilla ones from Google's store, like Instagram, Twitter's official client, etc.), but of course really well-crafted malware would be tough to guard against or to spot. And even if they can be defeated, more and more sites (Facebook, for one) now play video just because I've rolled over a thumbnail. Read on for second part of the question.