Chou shows the new HTC One M8 phone during a launch event in New York
HTC CEO Peter Chou shows the new HTC One M8 phone during a launch event in New York March 25, 2014. The HTC One M8 has a 5-inch display, slightly larger than its predecessor, as well as improved camera technology, a faster processor and updated software, the company said.REUTERS/Brendan McDermid

Crowd-sourced custom ROM developer community CyanogenMod has rolled-out the new CM12.1 series firmware to the 2014 flagship HTC One M8.

This new CM12.1 update comes with a critical software-patch, which is said to fix Stagefright bug. If this flaw is left unchecked, it will leave the smartphones vulnerable to data theft. Cyber-criminals can take control of the Android smartphone with just an MMS riddled with malicious code.

Read more: Android Stagefright Bug: How to Minimize its Vulnerability on phone and Everything You Need to Know

Prerequisites (Things to remember before installing the CyanogenMod CM12 snapshot):

  1. Make sure the device is rooted before going forward with custom ROM installation
  2. This new CyanogenMod CM12.1 Android 5.1.1 Lollipop custom ROM has to be installed on the HTC One M8 models only ; if tried on other devices, it might get bricked [To check your device model: Go to Settings >> About phone >> model number]
  3. Installation of custom ROM requires clearing of memory in the smartphone, so make sure to back all the data by installing Clockwork Mod (CWM) Recovery/ TWRP in the smartphone.
  4. Make sure you have installed USB drivers on the PC, or else your smartphone (HTC One M8) will not be recognised by the computer.
  5. Make sure your device has more than 80% battery, or else there is a chance of smartphone getting temporarily bricked if the installation process is interrupted mid-way.

[Disclaimer:This procedure is very technical and should be performed by a person with sound knowledge of rooting (or manual software installation) Android devices. If the step-by-step installation process is not followed properly, there are chances of the smartphone getting bricked or being permanently irreparable. International Business Times, India Edition cannot be held responsible for any damage or claims from readers if the procedure does not yield the required results or if the smartphone is bricked. Hence, users are advised to proceed with caution.]

CyanogenMod CM12.1 Downloadable files:

HTC One M8 CM12.1: HERE [Build date: 26/08/2015]

Cyanogen Recovery: HERE

Google Apps: HERE

Step-by-step installation procedure of CyanogenMod CM12.1 Android 5.1.1 Lollipop custom ROM on HTC One M8:

Step 1: After downloading the new CM12.1 custom ROM and Google Apps in to the PC, connect HTC One M7 to the Computer via USB cord.

[Note: Before plugging the phone to the computer, be sure that you have installed USB driver software, if not, click HERE to download the firmware]

Step 2: Place Android 5.1.1 Lollipop custom ROM zip file and Google Apps file into the phone's SD card memory. [Note: Users are advised to paste the .zip file in SD card root, not in any other folder.]

[Note: Before installing the custom software, be sure that the device must have been rooted and has installed ClockworkMod Recovery tool.]

Step 3: Later, place boot.img file in the android-sdk-windows platform-tools directory

Step 4: Now, turn off the device and disconnect from the PC.

Step 5: Perform the regular Bootloader mode sortie, by press holding 'Volume (down)', and 'Power' buttons.

Step 6: After entering the Bootloader mode (on the phone), go to android-sdk-windowsplatform-tools (on the PC) and open Command prompt and type in: 'fastboot flash boot boot.img' and press enter.

(To enter Command prompt: Shift + right-click >> open command Prompt)

Step 7: Type: 'fastboot reboot' and follow instructions displayed on the screen. Select BOOTLOADER option to enter Recovery Mode

Step 8: Once entering the Recovery mode, clear the phone memory, by choosing 'wipe data/factory reset'

[Note: use Volume keys to navigate and power button to select options, while operating under Recovery Mode]

Step 9: Clear the cache memory by selecting 'wipe cache partition'.

Step 10: Go back to ClockworkMod recovery, and select 'advanced' and tap 'wipe dalvik cache' [Note: This step is optional, but many recommend this procedure so that user will not face boot loops or any other errors in the middle of custom ROM installation]

Step 11: Come back to main recovery screen and then tap 'install zip from SD card'

Step 13: Tap 'choose zip from sdcard' and go to Android 5.1.1 Lollipop ROM .zip file in SD card and enter the installation process. Repeat the procedure for installing Google Apps [Note: use 'Volume' keys to navigate and 'Power' button to select options]

Step 14: Once done with the installation process, navigate to '+++++Go Back+++++' and re-start the device by opting 'reboot system now' seen in the recovery menu.

Now, your device (HTC One M8) will take at a few minutes to complete the booting process.

Users then head to Settings >> select 'About phone' to confirm the installation of CyanogenMod CM12.1 Android 5.1.1 Lollipop custom ROM.

[Credits: CyanogenMod.org]