Introduction to SUID Executables
A well-known way to gain root privilege in Linux is by using SUID Executables. SUID (SetUID) is a permission given to a program that allows users to execute the program as if the owner of the program were executing it. Thus, if a program is owned by root, a user temporarily has root privilege during the execution of that program. It is possible, therefore, to exploit SUID executables in order to arbitrarily execute commands as root and maintain root privilege.