lsfs in AIX 4.x allows a local user to gain additional privileges by creating Trojan horse programs named (1) grep or (2) lslv in a certain directory that is under the user's control, which cause lsfs to access the programs in that directory.
diagrpt in AIX 4.3.x and 5.1 uses the DIAGDATADIR environment variable to find and execute certain programs, which allows local users to gain privileges by modifying the variable to point to a Trojan horse program.