sudo not working in macOS sequoia

I'm trying to enter into superuser using sudo su but it's not working, I'm getting following output on screen, sudo: /etc/sudoers is world writable sudo: no valid sudoers sources found, quitting sudo: error initializing audit plugin sudoers_audit even when I try, sudo reboot it's showing same output and not rebooting. I don't know if any file is broken or corrupted on my system. Changing permissions is also not working out for me. Getting following output, chmod: Unable to change file mode /etc/sudoers: Operation not permitted Thanks in advanced.