SzafirHost downloads necessary files in the context of the initiating web page. When called, SzafirHost updates its dynamic library. JAR files are correctly verified based on a list of trusted file hashes, and if a file was not on that list, it was checked to see if it had been digitally signed by the vendor. The application doesn't verify hash or vendor's digital signature of uploaded DLL, SO, JNILIB or DYLIB file. The attacker can provide malicious file which will be saved in users /temp folder and executed by the application. This issue was fixed in version 1.1.0.