Local Java applets may read contents of local file system
Security researcher Georgi Guninski reported an issue with Java applets where in some circumstances the applet could access files on the local system when loaded using the a file:/// URI and violate file origin policy due to interaction with the codebase parameter. This affects applets running on the local file system. Mozilla developer John Schoenick later discovered that fixes for this issue were inadequate and allowed the invocation of Java applets to bypass security checks in additional circumstances. This could lead to untrusted Java applets having read-only access on the local files system if used in conjunction with a method to download a file to a known or guessable path.