debian-cis/bin/hardening/1.5.1_restrict_core_dumps.sh

#!/bin/bash

# run-shellcheck
#
# CIS Debian Hardening
#

#
# 1.5.1 Ensure core dumps are restricted (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="Restrict core dumps."

LIMIT_FILE='/etc/security/limits.conf'
LIMIT_DIR='/etc/security/limits.d'
LIMIT_PATTERN='^\*[[:space:]]*hard[[:space:]]*core[[:space:]]*0$'
SYSCTL_PARAM='fs.suid_dumpable'
SYSCTL_EXP_RESULT=0

# This function will be called if the script status is on enabled / audit mode
audit() {
    SEARCH_RES=0
    LIMIT_FILES=""
    if $SUDO_CMD [ -d "$LIMIT_DIR" ]; then
        for file in $($SUDO_CMD ls "$LIMIT_DIR"/*.conf 2>/dev/null); do
            LIMIT_FILES="$LIMIT_FILES $LIMIT_DIR/$file"
        done
    fi
    debug "Files to search $LIMIT_FILE $LIMIT_FILES"
    for file in $LIMIT_FILE $LIMIT_FILES; do
        does_pattern_exist_in_file "$file" "$LIMIT_PATTERN"
        if [ "$FNRET" != 0 ]; then
            debug "$LIMIT_PATTERN not present in $file"
        else
            ok "$LIMIT_PATTERN present in $file"
            SEARCH_RES=1
            break
        fi
    done
    if [ "$SEARCH_RES" = 0 ]; then
        crit "$LIMIT_PATTERN is not present in $LIMIT_FILE $LIMIT_FILES"
    fi
    has_sysctl_param_expected_result "$SYSCTL_PARAM" "$SYSCTL_EXP_RESULT"
    if [ "$FNRET" != 0 ]; then
        crit "$SYSCTL_PARAM was not set to $SYSCTL_EXP_RESULT"
    elif [ "$FNRET" = 255 ]; then
        warn "$SYSCTL_PARAM does not exist -- Typo?"
    else
        ok "$SYSCTL_PARAM correctly set to $SYSCTL_EXP_RESULT"
    fi
}

# This function will be called if the script status is on enabled mode
apply() {
    does_pattern_exist_in_file "$LIMIT_FILE" "$LIMIT_PATTERN"
    if [ "$FNRET" != 0 ]; then
        warn "$LIMIT_PATTERN not present in $LIMIT_FILE, adding at the end of  $LIMIT_FILE"
        add_end_of_file $LIMIT_FILE "* hard core 0"
    else
        ok "$LIMIT_PATTERN present in $LIMIT_FILE"
    fi
    has_sysctl_param_expected_result "$SYSCTL_PARAM" "$SYSCTL_EXP_RESULT"
    if [ "$FNRET" != 0 ]; then
        warn "$SYSCTL_PARAM was not set to $SYSCTL_EXP_RESULT -- Fixing"
        set_sysctl_param "$SYSCTL_PARAM" "$SYSCTL_EXP_RESULT"
    elif [ "$FNRET" = 255 ]; then
        warn "$SYSCTL_PARAM does not exist -- Typo?"
    else
        ok "$SYSCTL_PARAM correctly set to $SYSCTL_EXP_RESULT"
    fi

}

# This function will check config parameters required
check_config() {
    :
}

# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
    # shellcheck source=../../debian/default
    . /etc/default/cis-hardening
fi
if [ -z "$CIS_ROOT_DIR" ]; then
    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
    echo "Cannot source CIS_ROOT_DIR variable, aborting."
    exit 128
fi

# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
if [ -r "$CIS_ROOT_DIR"/lib/main.sh ]; then
    # shellcheck source=../../lib/main.sh
    . "$CIS_ROOT_DIR"/lib/main.sh
else
    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_ROOT_DIR in /etc/default/cis-hardening"
    exit 128
fi