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#!/bin/sh
#################################################################################
#
# Lynis
# ------------------
#
# Copyright 2007-2013, Michael Boelen
# Copyright 2007-2017, CISOfy
#
# Website : https://cisofy.com
# Blog : http://linux-audit.com
# GitHub : https://github.com/CISOfy/lynis
#
# Lynis comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
# welcome to redistribute it under the terms of the GNU General Public License.
# See LICENSE file for usage of this software.
#
#################################################################################
#
# Scheduled tasks
#
#################################################################################
#
InsertSection "Scheduled tasks"
#
#################################################################################
#
ATD_RUNNING=0
CROND_RUNNING=0
#
#################################################################################
#
# Test : SCHD-7702
# Description : Check cron daemon
Register --test-no SCHD-7702 --weight L --network NO --category security --description "Check status of cron daemon"
if [ ${SKIPTEST} -eq 0 ]; then
FIND=$(ps aux | ${EGREPBINARY} "( cron$|/cron(d)? )")
if [ "${FIND}" = "" ]; then
LogText "Result: no cron daemon found"
else
LogText "Result: cron daemon running"
CROND_RUNNING=1
Report "crond_running=1"
Report "scheduler[]=crond"
fi
fi
#
#################################################################################
#
# Test : SCHD-7704
# Description : Check crontab / cronjobs
Register --test-no SCHD-7704 --weight L --network NO --category security --description "Check crontab/cronjobs"
if [ ${SKIPTEST} -eq 0 ]; then
BAD_FILE_PERMISSIONS=0
BAD_FILE_OWNERSHIP=0
FindCronJob() {
sCRONJOBS=$(${EGREPBINARY} '^([0-9*])' $1 | ${TRBINARY} '\t' ' ' | ${TRBINARY} -s ' ' | ${TRBINARY} ' ' ',')
}
CRONTAB_FILE="/etc/crontab"
if [ -f ${CRONTAB_FILE} ]; then
if IsWorldWritable ${CRONTAB_FILE}; then LogText "Result: insecure file permissions for cronjob file ${CRONTAB_FILE}"; Report "insecure_fileperms_cronjob[]=${CRONTAB_FILE}"; BAD_FILE_PERMISSIONS=1; AddHP 0 5; fi
if ! IsOwnedByRoot ${CRONTAB_FILE}; then LogText "Result: incorrect owner found for cronjob file ${CRONTAB_FILE}"; Report "bad_fileowner_cronjob[]=${CRONTAB_FILE}"; BAD_FILE_OWNERSHIP=1; AddHP 0 5; fi
FindCronJob ${CRONTAB_FILE}
for I in ${sCRONJOBS}; do
LogText "Found cronjob (${CRONTAB_FILE}): ${I}"
Report "cronjob[]=${I}"
done
fi
CRON_DIRS="/etc/cron.d"
for I in ${CRON_DIRS}; do
LogText "Test: checking directory ${I}"
if [ -d ${I} ]; then
FileIsReadable ${I}
if [ ${CANREAD} -eq 1 ]; then
LogText "Result: found directory ${I}"
LogText "Test: searching files in ${I}"
FIND=$(find ${I} -type f -print | ${GREPBINARY} -v ".placeholder")
if [ "${FIND}" = "" ]; then
LogText "Result: no files found in ${I}"
else
LogText "Result: found one or more files in ${I}. Analyzing files.."
for J in ${FIND}; do
if IsWorldWritable ${J}; then LogText "Result: insecure file permissions for cronjob file ${J}"; Report "insecure_fileperms_cronjob[]=${J}"; BAD_FILE_PERMISSIONS=1; AddHP 0 5; fi
if ! IsOwnedByRoot ${J}; then LogText "Result: incorrect owner found for cronjob file ${J}"; Report "bad_fileowner_cronjob[]=${J}"; BAD_FILE_OWNERSHIP=1; AddHP 0 5; fi
FindCronJob ${J}
if [ ! "${sCRONJOBS}" = "" ]; then
for K in ${sCRONJOBS}; do
LogText "Result: Found cronjob (${J}): ${K}"
Report "cronjob[]=${J}"
done
fi
done
LogText "Result: done with analyzing files in ${I}"
fi
else
LogText "Result: can not read file or directory ${I}"
fi
else
LogText "Result: directory ${I} does not exist"
fi
done
CRON_DIRS="/etc/cron.hourly /etc/cron.daily /etc/cron.weekly /etc/cron.monthly"
for I in ${CRON_DIRS}; do
LogText "Test: checking directory ${I}"
if [ -d ${I} ]; then
LogText "Result: found directory ${I}"
LogText "Test: searching files in ${I}"
FIND=$(find ${I} -type f -print | ${GREPBINARY} -v ".placeholder")
if [ "${FIND}" = "" ]; then
LogText "Result: no files found in ${I}"
else
LogText "Result: found one or more files in ${I}. Analyzing files.."
for J in ${FIND}; do
if IsWorldWritable ${J}; then LogText "Result: insecure file permissions for cronjob file ${J}"; Report "insecure_fileperms_cronjob[]=${J}"; BAD_FILE_PERMISSIONS=1; AddHP 0 5; fi
if ! IsOwnedByRoot ${J}; then LogText "Result: incorrect owner found for cronjob file ${J}"; Report "bad_fileowner_cronjob[]=${J}"; BAD_FILE_OWNERSHIP=1; AddHP 0 5; fi
LogText "Result: Found cronjob (${I}): ${J}"
Report "cronjob[]=${J}"
done
LogText "Result: done with analyzing files in ${I}"
fi
else
LogText "Result: directory ${I} does not exist"
fi
done
# /var/spool/cron/* and /var/spool/cron/crontabs/*
# Search only in one tree, to avoid searching the tree twice
if [ -d /var/spool/cron/crontabs ]; then
FIND=$(find /var/spool/cron/crontabs -type f -print)
for I in ${FIND}; do
FindCronJob ${I}
for J in ${sCRONJOBS}; do
LogText "Found cronjob (/var/spool/cron/crontabs): ${I} (${J})"
Report "cronjob[]=${I}"
done
done
else
if [ -d /var/spool/cron ]; then
FIND=$(find /var/spool/cron -type f -print)
for I in ${FIND}; do
FindCronJob ${I}
for J in ${sCRONJOBS}; do
LogText "Found cronjob (/var/spool/cron): ${I} (${J})"
LogText "cronjob[]=${I}"
done
done
fi
fi
# Anacron
if [ "${OS}" = "Linux" ]; then
if [ -f /etc/anacrontab ]; then
LogText "Test: checking anacrontab"
sANACRONJOBS=$(${EGREPBINARY} '^([0-9@])' /etc/anacrontab | ${TRBINARY} '\t' ' ' | ${TRBINARY} -s ' ' | ${TRBINARY} ' ' ',')
if [ ! "${sANACRONJOBS}" = "" ]; then
Report "scheduler[]=anacron"
for J in ${sANACRONJOBS}; do
LogText "Found anacron job (/etc/anacrontab): ${J}"
Report "cronjob[]=${J}"
done
fi
fi
fi
# Show warning when an issue shows up. Even if *both* the permissions and ownership are wrong, just show one (prevent overload of warnings).
if [ ${BAD_FILE_PERMISSIONS} -eq 1 ]; then
ReportWarning "${TEST_NO}" "Found one or more cronjob files with incorrect file permissions (see log for details)"
Display --indent 2 --text "- Checking crontab/cronjob" --result "${STATUS_WARNING}" --color RED
elif [ ${BAD_FILE_OWNERSHIP} -eq 1 ]; then
ReportWarning "${TEST_NO}" "Found one or more cronjob files with incorrect ownership (see log for details)"
Display --indent 2 --text "- Checking crontab/cronjob" --result "${STATUS_WARNING}" --color RED
else
Display --indent 2 --text "- Checking crontab/cronjob" --result "${STATUS_DONE}" --color GREEN
fi
fi
#
#################################################################################
#
# Test : SCHD-7718
# Description : Check atd status
Register --test-no SCHD-7718 --weight L --network NO --category security --description "Check at users"
if [ ${SKIPTEST} -eq 0 ]; then
LogText "Test: Checking atd status"
FIND=$(${PSBINARY} ax | ${GREPBINARY} "/atd" | ${GREPBINARY} -v "grep")
if [ ! "${FIND}" = "" ]; then
LogText "Result: at daemon active"
Display --indent 2 --text "- Checking atd status" --result "${STATUS_RUNNING}" --color GREEN
ATD_RUNNING=1
Report "scheduler[]=atd"
else
LogText "Result: at daemon not active"
if IsVerbose; then Display --indent 2 --text "- Checking atd status" --result "${STATUS_NOT_RUNNING}" --color WHITE; fi
fi
fi
#
#################################################################################
#
# Test : SCHD-7720
# Description : Check at users
# Notes : if at.allow exists, only users listed can schedule at jobs
# if at.allow does not exist, but at.deny does, everyone
# except the listed ones can schedule jobs. If both can't be
# found, only root can schedule jobs.
if [ ${ATD_RUNNING} -eq 1 ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi
Register --test-no SCHD-7720 --preqs-met ${PREQS_MET} --weight L --network NO --category security --description "Check at users"
if [ ${SKIPTEST} -eq 0 ]; then
AT_UNKNOWN=0
case ${OS} in
FreeBSD) AT_ALLOW="/var/at/at.allow"; AT_DENY="/var/at/at.deny" ;;
HPUX) AT_ALLOW="/usr/lib/cron/at.allow"; AT_DENY="/usr/lib/cron/at.deny" ;;
Linux) AT_ALLOW="/etc/at.allow"; AT_DENY="/etc/at.deny" ;;
OpenBSD) AT_ALLOW="/var/cron/at.allow"; AT_DENY="/var/cron/at.deny" ;;
SunOS) AT_ALLOW="/etc/cron.d/at.allow"; AT_DENY="/etc/cron.d/at.deny" ;;
*) AT_UNKNOWN=1; LogText "Test skipped, files for at unknown" ;;
esac
if [ ${AT_UNKNOWN} -eq 0 ]; then
LogText "Test: checking for file ${AT_ALLOW}"
if [ -f ${AT_ALLOW} ]; then
FileIsReadable ${AT_ALLOW}
if [ ${CANREAD} -eq 1 ]; then
LogText "Result: file ${AT_ALLOW} exists, only listed users can schedule at jobs"
FIND=$(${SORTBINARY} ${AT_ALLOW})
if [ "${FIND}" = "" ]; then
LogText "Result: File empty, no users are allowed to schedule at jobs"
else
for I in ${FIND}; do
LogText "Allowed at user: ${I}"
done
fi
else
LogText "Result: can not read ${AT_ALLOW} (no permission)"
fi
else
LogText "Result: file ${AT_ALLOW} does not exist"
LogText "Test: checking for file ${AT_DENY}"
if [ -f ${AT_DENY} ]; then
FileIsReadable ${AT_DENY}
if [ ${CANREAD} -eq 1 ]; then
LogText "Result: file ${AT_DENY} exists, only non listed users can schedule at jobs"
FIND=$(${SORTBINARY} ${AT_DENY})
if [ "${FIND}" = "" ]; then
LogText "Result: file is empty, no users are denied access to schedule jobs"
else
for I in ${FIND}; do
LogText "Denied at user: ${I}"
done
fi
else
LogText "Result: can not read ${AT_DENY} (no permission)"
fi
else
LogText "Result: both ${AT_ALLOW} and ${AT_DENY} do not exist"
LogText "Note: only root can schedule at jobs"
AddHP 1 1
fi
fi
Display --indent 4 --text "- Checking at users" --result "${STATUS_DONE}" --color GREEN
else
Display --indent 4 --text "- Checking at users" --result "${STATUS_SKIPPED}" --color YELLOW
fi
fi
#
#################################################################################
#
# Test : SCHD-7724
# Description : Check scheduled at jobs
if [ ${ATD_RUNNING} -eq 1 ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi
Register --test-no SCHD-7724 --preqs-met ${PREQS_MET} --weight L --network NO --category security --description "Check at jobs"
if [ ${SKIPTEST} -eq 0 ]; then
LogText "Test: Check scheduled at jobs"
FIND=$(atq | ${GREPBINARY} -v "no files in queue" | ${AWKBINARY} '{gsub("\t"," ");print}' | ${SEDBINARY} 's/ /!space!/g')
if [ ! "${FIND}" = "" ]; then
LogText "Result: found one or more jobs"
for I in ${FIND}; do
VALUE=$(echo ${I} | ${SEDBINARY} 's/!space!/ /g')
LogText "Found at job: ${VALUE}"
done
Display --indent 4 --text "- Checking at jobs" --result "${STATUS_FOUND}" --color GREEN
else
LogText "Result: no pending at jobs"
Display --indent 4 --text "- Checking at jobs" --result "${STATUS_NONE}" --color GREEN
fi
fi
#
#################################################################################
#
WaitForKeyPress
#
#================================================================================
# Lynis - Security Auditing and System Hardening for Linux and UNIX - https://cisofy.com
|