Linux Permissions
All tools and software you need is installed.
- Disable Compilers
chmod 000 /usr/bin/as >/dev/null 2>&1 chmod 000 /usr/bin/cc >/dev/null 2>&1 chmod 000 /usr/bin/gcc >/dev/null 2>&1 chmod 000 /usr/bin/c++ >/dev/null 2>&1 chmod 000 /usr/bin/g++ >/dev/null 2>&1 # chmod 000 /usr/bin/byacc >/dev/null 2>&1 # chmod 000 /usr/bin/yacc >/dev/null 2>&1 # chmod 000 /usr/bin/kgcc >/dev/null 2>&1
- Restrict read access
# System Logs
chmod -R g-wx,o-rwx /var/log/*
chown root:root /var/log/*
# ssh Server Config files
chmod og-rwx /etc/ssh/sshd_config
chown root:root /etc/ssh/sshd_config
# passwd file
chmod 644 /etc/passwd
chown root:root /etc/passwd
# Shadow file
chmod o-rwx,g-wx /etc/shadow
chown root:root /etc/shadow
# group's file
chmod 644 /etc/group
chown root:root /etc/group
# gshadow
chmod o-rwx,g-rx /etc/gshadow
chown root:root /etc/gshadow
# passwd file
chmod 644 /etc/passwd-
chown root:root /etc/passwd-
# Shadow file
chmod o-rwx,g-wx /etc/shadow-
chown root:root /etc/shadow-
# group's file
chmod 644 /etc/group-
chown root:root /etc/group-
# gshadow
chmod o-rwx,g-rx /etc/gshadow-
chown root:root /etc/gshadow-
- Restrict Virtual Partitions
mount -o remount,noexec /tmp
mount -o remount,rw,hidepid=2 /proc
mount -o remount,noexec /dev
mount -o remount,nodev /run