~]# which chmod
/bin/chmod
~]# chmod 000 /bin/chmod
~]# chmod 755 /bin/chmod
Use acl utility to correct permission as below:;
~]# setfacl -m u::x /bin/chmod
]# ll /bin/chmod
---x------ 1 root root 48712 Jun 25 2014 /bin/chmod
~]# chmod 755 /bin/chmod