During an initial installation of Oracle software on UNIX platforms, the Oracle Universal Installer creates the directory /tmp/orainstall (owned by oracle owner (Operating System, dba) with permissions of 711. In that directory, the Installer creates a shell script called orainstRoot.sh with permissions of 777. Thereafter, the Installer pauses and displays a dialog box requesting that this script be run as root from another window. Exiting the Installer deletes both the file and the directory.
As such, any user aware of the script, orainstRoot.sh, may run privileged Unix shell commands by editing it before root executes it and thus comprises the system.
Likelihood of Occurrence
This problem only occurs on an initial installation of Oracle on UNIX platforms.
All Oracle software including the Database Server
There is a simple solution to this problem.