Ubuntu: (CVE-2017-6903): ioquake3 vulnerability

In ioquake3 before 2017-03-14, the auto-downloading feature has insufficient content restrictions. This also affects Quake III Arena, OpenArena, OpenJK, iortcw, and other id Tech 3 (aka Quake 3 engine) forks. A malicious auto-downloaded file can trigger loading of crafted auto-downloaded files as native code DLLs. A malicious auto-downloaded file can contain configuration defaults that override the user's. Executable bytecode in a malicious auto-downloaded file can set configuration variables to values that will result in unwanted native code DLLs being loaded, resulting in sandbox escape.