Crossroads 2.81 does not properly handle the /tmp directory during a build of xr

Crossroads 2.81 does not properly handle the /tmp directory during a build of xr. A local attacker can first create a world-writable subdirectory in a certain location under the /tmp directory, wait until a user process copies xr there, and then replace the entire contents of this subdirectory to include a Trojan horse xr.