ORA-12547: TNS:lost contact because to insufficent permissions on /dev/null file system

Today when i try to connect one of our database server  I found the below error message.

#>sqlplus / as sysdba

ORA-12547: TNS:lost contact

when i checked in alert log i found the below error:

Process J003 died, see its trace file

kkjcre1p: unable to spawn jobq slave process

Errors in file /oracle/app/diag/rdbms/a1/A1/trace/A1_cjq0_5767576.trc

After lots of investigation i found that the permissions of /dev/null is changed.

# ls -l /dev/null*
crw-r--r--    1 root     system        2,  2 Dec 02 20:37 /dev/null
-rw-r--r--    1 root     system      6807316 Dec 02 20:38 /dev/null 2>&1

only root has permissions to write on /dev/null file system.I see some one has changed the permissions for this file. after giving write permissions i am able to connect to oracle. below are the steps to change the permissions.

#cd /dev

#chmod go+w null*

# ls -l /dev/null*
crw-rw-rw-    1 root     system        2,  2 Dec 02 20:37 /dev/null
-rw-rw-rw-    1 root     system      6807316 Dec 02 20:38 /dev/null 2>&1