Some magic to remount /system First of all:
Phone's model is Alcatel One Touch Idol Mini / 6012X
Chipset model is MT6572

The short version:

The device is in boot loop and to resolve this I must rename a file. The problem is that the file is in /system and I haven't granted ADB superuser permissions (So ADB simply hangs on "su", even when running scripts through ADB. Also "at" is not installed). Another problem is that I haven't installed a custom recovery and, more importantly, I haven't even unlocked the boot loader. 

I can't manage to install custom images via SP Flash Tool (SP Flash Tool doesn't find the device although the VCOM USB drivers are installed).

What's worse than this? Alcatel doesn't provide a way to reflash the stock ROM.

So, my question:
Is there some kind of magic to force "su" to execute through adb without adb being granted permission by SuperSU?
According to this thread, your device is rootable using framaroot.

As you only need a temproot, the first thing to try would be to:


extract the temproot binary used by framaroot and push it to /data/local/tmp or any folder where you can set permissions
flag this file as executable then run it

$ chmod 777 filename
$ ./filename

if successful, you have temp root and can remount the system read/write

# mount -o remount,rw /system /system