Write permission on certain paths, like the SD card (extSdCard) In an attempt to transfer a file from a remote server to an Android device I ran into permission problems.
It turns out that I do not have a write permission at the location of the SD card (/mnt/extSdCard).
I am using SSHDroid as an ssh server on the Android device and vSSH as an ssh client to engage in ssh on the Android device.
Since both sudo and su seem to be absent on the ssh server app (SSHDroid), I am wondering how I can change/get permission to write to the SD card location. Or is root privilege not enough to  change write permissions, and is this thus governed solely by the Android OS, so a limitation of the OS?
What I can do is write to the home path of the ssh server (SSHDroid). This path, however, is very cumbersome and can not be reached from the regular Android file browser. This is the reason why I wanted to transfer the file to an accessible path, like the SD card.
Supplement. The Android version is 4.4.2. The kernel version is 3.4.0-1539356#1.
One of the restrictions introduced with 4.4-kitkat was moving the WRITE_EXTERNAL_STORAGE permission to protection-level "SignatureOrSystem", which means even if requested, a "normal app" (i.e. one you install yourself as "normal user" without any root specialities) will no longer get it granted. So there are very few things you can do to "work around" this:


obviously: rooting the device, and removing this limit
using the app's "personal" directory as storage for your sync'd files (i.e. &lt;sdcard&gt;/Android/data/&lt;package_name&gt;/, as this is the only place an app can write on SD with Kitkat)
using your internal-sd card as storage (as here the limitation does not apply)