If the solution from @Aragorn fails (as k3B did for me…):
The required rights and group membership can be set with the following commands.
sudo chmod 4710 /usr/bin/cdrdao
sudo chmod 4710 /usr/bin/cdrecord
sudo chmod 0750 /usr/bin/growisofs
sudo chmod 4710 /usr/sbin/cdrdao
sudo chmod 4710 /usr/sbin/cdrecord
sudo chmod 0750 /usr/sbin/growisofs
sudo chmod 4710 /sbin/cdrdao
sudo chmod 4710 /sbin/cdrecord
sudo chmod 750 /sbin/growisofs
sudo chown root:optical /usr/bin/cdrecord
sudo chown root:optical /usr/bin/cdrdao
sudo chown root:optical /usr/bin/growisofs
Finaly add your user to GROUP optical:
[[sudo usermod -g optical <MyUserName> ]] the below is the most accurate (thanks @Aragorn)
sudo usermod -a <MyUserName> -G optical
After these measures, k3B worked pretty fine again for me.
(credits for the solution go to K3b can’t burn ISO image )