In FlightGear before version 2017.3.1, Main/logger.cxx in the FGLogger subsystem allows one to overwrite any file via a resource that affects the contents of the global Property Tree.
In FlightGear before 2017.2.1, the FGCommand interface allows overwriting any file the user has write access to, but not with arbitrary data: only with the contents of a FlightGear flightplan (XML). A resource such as a malicious third-party aircraft could exploit this to damage files belonging to the user. Both this issue and CVE-2016-9956 are directory traversal vulnerabilities in Autopilot/route_mgr.cxx - this one exists because of an incomplete fix for CVE-2016-9956.
Multiple format string vulnerabilities in FlightGear 2.6 and earlier and SimGear 2.6 and earlier allow user-assisted remote attackers to cause a denial of service and possibly execute arbitrary code via format string specifiers in certain data chunk values in an aircraft xml model to (1) fgfs/flightgear/src/Cockpit/panel.cxx or (2) fgfs/flightgear/src/Network/generic.cxx, or (3) a scene graph model to simgear/simgear/scene/model/SGText.cxx.
Multiple buffer overflows in FlightGear 2.6 and earlier and SimGear 2.6 and earlier allow user-assisted remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a (1) long string in a rotor tag of an aircraft xml model to the Rotor::getValueforFGSet function in src/FDM/YASim/Rotor.cpp or (2) a crafted UDP packet to the SGSocketUDP::read function in simgear/simgear/simgear/io/sg_socket_udp.cxx.