Linux file Special permissions-SetUID

01, setuid function: Ordinary users in the execution of the command, will temporarily obtain the identity of the owner, ordinary users of the program must have Execute permissions

02, SetUID =

(01) Only binary programs can be set

(02) The executor of the command must have execute (x) permission

(03) The command executor obtains the identity of the file owner when executing the program;

SetUID permissions are valid only during program operation

(05) Set SetUID = CHOMD 4755/file path 4 for SetUID permissions

CHOMD u+s/file path

(06) Cancel SetUID = CHOMD 755/file path

CHOMD u-s/file path

03. Dangerous setuid

(01), the key directory should strictly control the write permission. such as "/", "usr", etc.

(02), the user's password set to strictly abide by the password three principles

(03), to the system should have setuid permissions of the file as a list, is to see if there is no such file is set setuid permissions

Linux file Special permissions-SetUID