According to § 5 Abs. 1 of the German Copyright law, official works like coats of arms are gemeinfrei (in the public domain). However please be aware: Depending on context the use of this flag is banned or even illegal in Germany, Austria, Hungary, Poland, Czech Republic, France, Brazil and other countries, by other laws beyond copyright (for details please see below).
Legal disclaimer This image shows (or resembles) a symbol that was used by the National Socialist (NSDAP/Nazi) government of Germany or an organization closely associated to it, or another party which has been banned by the Federal Constitutional Court of Germany.