I have done a similar thing but have not tried to access it from a web app. Have you put an entry in /etc/fstab so that the windows partitions can be mounted automatically? If not, you can add something like this to your /etc/fstab file:
//<windowsServer>/<shareName> /<pathToMountPoint> cifs guest 0 0
After that, umount the partition from the location you currently have it, then run:
This will cause all entries in /etc/fstab to be mounted if they are done correctly.
after that, you shouldn't need password anymore.