debian-cis/bin/hardening/6.1.13_find_suid_files.sh
P-EB 32886d3a3d
Replace CIS_ROOT_DIR by a more flexible system (#204)
* Replace CIS_ROOT_DIR by a more flexible system

* Try to adapt the logic change to the functional tests
2023-09-25 14:24:01 +02:00

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#!/bin/bash
# run-shellcheck
#
# CIS Debian Hardening
#
#
# 6.1.13 Audit SUID executables (Not Scored)
#
set -e # One error, it's over
set -u # One variable unset, it's over
# shellcheck disable=2034
HARDENING_LEVEL=2
# shellcheck disable=2034
DESCRIPTION="Find SUID system executables."
IGNORED_PATH=''
# find emits following error if directory or file disappear during
# tree traversal: find: /tmp/xxx: No such file or directory
FIND_IGNORE_NOSUCHFILE_ERR=false
# This function will be called if the script status is on enabled / audit mode
audit() {
info "Checking if there are suid files"
if [ -n "$IGNORED_PATH" ]; then
# maybe IGNORED_PATH allow us to filter out some FS
FS_NAMES=$(df --local -P | awk '{if (NR!=1) print $6}' | grep -vE "$IGNORED_PATH")
[ "${FIND_IGNORE_NOSUCHFILE_ERR}" = true ] && set +e
# shellcheck disable=2086
FOUND_BINARIES=$($SUDO_CMD find $FS_NAMES -xdev -ignore_readdir_race -type f -perm -4000 -regextype 'egrep' ! -regex $IGNORED_PATH -print)
[ "${FIND_IGNORE_NOSUCHFILE_ERR}" = true ] && set -e
else
FS_NAMES=$(df --local -P | awk '{if (NR!=1) print $6}')
[ "${FIND_IGNORE_NOSUCHFILE_ERR}" = true ] && set +e
# shellcheck disable=2086
FOUND_BINARIES=$($SUDO_CMD find $FS_NAMES -xdev -ignore_readdir_race -type f -perm -4000 -print)
[ "${FIND_IGNORE_NOSUCHFILE_ERR}" = true ] && set -e
fi
BAD_BINARIES=""
for BINARY in $FOUND_BINARIES; do
if grep -qw "$BINARY" <<<"$EXCEPTIONS"; then
debug "$BINARY is confirmed as an exception"
else
BAD_BINARIES="$BAD_BINARIES $BINARY"
fi
done
if [ -n "$BAD_BINARIES" ]; then
crit "Some suid files are present"
# shellcheck disable=SC2001
FORMATTED_RESULT=$(sed "s/ /\n/g" <<<"$BAD_BINARIES" | sort | uniq | tr '\n' ' ')
crit "$FORMATTED_RESULT"
else
ok "No unknown suid files found"
fi
}
# This function will be called if the script status is on enabled mode
apply() {
info "Removing suid on valid binary may seriously harm your system, report only here"
}
# This function will create the config file for this check with default values
create_config() {
cat <<EOF
status=audit
# Put Here your valid suid binaries so that they do not appear during the audit
EXCEPTIONS="/bin/mount /usr/bin/mount /bin/ping /usr/bin/ping /bin/ping6 /usr/bin/ping6 /bin/su /usr/bin/su /bin/umount /usr/bin/umount /usr/bin/chfn /usr/bin/chsh /usr/bin/fping /usr/bin/fping6 /usr/bin/gpasswd /usr/bin/mtr /usr/bin/newgrp /usr/bin/passwd /usr/bin/sudo /usr/bin/sudoedit /usr/lib/openssh/ssh-keysign /usr/lib/pt_chown /usr/bin/at"
EOF
}
# This function will check config parameters required
check_config() {
# No param for this function
:
}
# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
# shellcheck source=../../debian/default
. /etc/default/cis-hardening
fi
if [ -z "$CIS_LIB_DIR" ]; then
echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
echo "Cannot source CIS_LIB_DIR variable, aborting."
exit 128
fi
# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
# shellcheck source=../../lib/main.sh
. "${CIS_LIB_DIR}"/main.sh
else
echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
exit 128
fi