Sony has started rolling out new firmware update for Xperia Z series phones, which will fix the recently discovered Stagefright vulnerability. Currently, the new update (build 23.4.A.0.580) will be available for Xperia Z2, Xperia Z3 and Xperia Z3 Compact devices in some parts of the world and the OTA update notification will be appeared on your device soon.
If you have not received the OTA notification due to root access, there is a way to fix the Stagefright vulnerability on rooted Xperia Z series devices without downloading the full 1.4GB firmware. Thanks to the XDA user manipars for creating ‘Stagefright patch’ for Xperia devices running on Android 5.1.1 Lollipop. This flashable zip file updates all the 35 libstagefright libraries to the latest version.
The Stagefright patch explained here is originally created from the Xperia Z3 Compact stock firmware (23.4.A.0.580), but it has been reportedly working on all rooted Xperia devices running on Android 5.1.1 Lollipop, since Sony usually do share the same libraries for all devices.
Note: Your Xperia Z series device should be rooted and running on Android 5.1.1 Lollipop. Do not try it on other version of Android, which may causes for bootloop issue.
1. First, make a backup of current ROM from custom recovery, just in case.
2. Download the Stagefright lib update patch [HERE] and move the zip file to your phone’s SD card.
3. Boot your phone into custom recovery mode and flash the ‘Stagefright lib update patch’ zip file.
4. Reboot your Xperia device.
Alternatively, there is a temporary method to fix the critical Stagefright vulnerability for all Android phones. Check this post for details.