There are several possibilities to fund your master thesis

Austrian grants

http://www.grants.at

This is an Austrian data base for research  grants and other research funding possibilities. You can find various types of funding, including grants for master theses, doctoral theses, as well as funding for research abroad.

Grants from the University of Vienna

http://stipendien.univie.ac.at

Here you can find the performance scholarship ("Leistungsstipendium") as well as the research scholarship ("Förderstipendium")

The latter also includes possibilities to fund master thesis related travels abroad as well as payment of probands.

International grants

http://www.scholarshipportal.eu/

Data base with international grants and funding possibilities