#!/bin/sh # unix-privesc-check - Checks Unix system for simple privilege escalations # Copyright (C) 2008 pentestmonkey@pentestmonkey.net # # # License # ------- # This tool may be used for legal purposes only. Users take full responsibility # for any actions performed using this tool. The author accepts no liability # for damage caused by this tool. If you do not accept these condition then # you are prohibited from using this tool. # # In all other respects the GPL version 2 applies: # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License version 2 as # published by the Free Software Foundation. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License along # with this program; if not, write to the Free Software Foundation, Inc., # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. # # You are encouraged to send comments, improvements or suggestions to # me at pentestmonkey@pentestmonkey.net # # # Description # ----------- # Auditing tool to check for weak file permissions and other problems that # may allow local attackers to escalate privileges. # # It is intended to be run by security auditors and pentetration testers # against systems they have been engaged to assess, and also by system # admnisitrators who want to check for "obvious" misconfigurations. It # can even be run as a cron job so you can check regularly for misconfigurations # that might be introduced. # # Ensure that you have the appropriate legal permission before running it # someone else's system. # # TODO List # --------- # There's still plenty that this script doesn't do... # - Doesn't work for shell scripts! These appear as "/bin/sh my.sh" in the process listing. # This script only checks the perms of /bin/sh. Not what we're after. :-( # - Similarly for perl scripts. Probably python, etc. too. # - Check /proc/pid/cmdline for absolute path names. Check security of these (e.g. /etc/snmp/snmpd.conf) # - Check everything in root's path - how to find root's path? # - /proc/pid/maps, smaps are readable and lists some shared objects. We should check these. # - /proc/pid/fd contain symlinks to all open files (but you can't see other people FDs) # - check for trust relationships in /etc/hosts.equiv # - NFS imports / exports / automounter # - Insecure stuff in /etc/fstab (e.g. allowing users to mount file systems) # - Inspecting people's PATH. tricky. maybe read from /proc/pid/environ, .bashrc, /etc/profile, .bash_profile # - Check if /etc/init.d/* scripts are readable. Advise user to audit them if they are. # - .exrc? # - X11 trusts, apache passwd files, mysql trusts? # - Daemons configured in an insecure way: tftpd, sadmind, rexd # - World writable dirs aren't as bad if the sticky bit is set. Check for this before reporting vulns. # - Maybe do a strings of binaries (and their .so's?) # - Do a better job of parsing cron lines - search for full paths # - Maybe LDPATHs from /etc/env.d # - Check if ldd, ld.so.conf changes have broken this script on non-linux systems. # - Avoid check certain paths e.g. /-/_ clearly isn't a real directory. # - create some sort of readable report # - indicate when it's likely a result is a false positive and when it's not. # - Skip pseudo processes e.g. [usb-storage] # - File permission on kernel modules # - Replace calls to echo with a my_echo func. Should be passed a string and an "importance" value: # - my_echo 1 "This is important and should always be printed out" # - my_echo 2 "This is less important and should only be printed in verbose mode" # - We check some files / dirs multiple times. Slow. Can we implement a cache? # - grep for PRIVATE KEY to find private ssh and ssl keys. Where to grep? # - check SGID programs VERSION="1.4" HOME_DIR_FILES=".netrc .ssh/id_rsa .ssh/id_dsa .rhosts .shosts .my.cnf .ssh/authorized_keys .bash_history .sh_history .forward" CONFIG_FILES="/etc/passwd /etc/group /etc/master.passwd /etc/inittab /etc/inetd.conf /etc/xinetd.con /etc/xinetd.d/* /etc/contab /etc/fstab /etc/profile /etc/sudoers" PGDIRS="/usr/local/pgsql/data ~postgres/postgresql/data ~postgres/data ~pgsql/data ~pgsql/pgsql/data /var/lib/postgresql/data /etc/postgresql/8.2/main /var/lib/pgsql/data" get_owner () { GET_OWNER_FILE=$1 GET_OWNER_RETURN=`ls -lLd "$GET_OWNER_FILE" | awk '{print $3}'` } get_group () { GET_GROUP_FILE=$1 GET_GROUP_RETURN=`ls -lLd "$GET_GROUP_FILE" | awk '{print $4}'` } usage () { echo "unix-privesc-check v$VERSION ( http://pentestmonkey.net/tools/unix-privesc-check )" echo echo "Usage: unix-privesc-check { standard | detailed }" echo echo '"standard" mode: Speed-optimised check of lots of security settings.' echo echo '"detailed" mode: Same as standard mode, but also checks perms of open file' echo ' handles and called files (e.g. parsed from shell scripts,' echo ' linked .so files). This mode is slow and prone to false ' echo ' positives but might help you find more subtle flaws in 3rd' echo ' party programs.' echo echo "This script checks file permissions and other settings that could allow" echo "local users to escalate privileges." echo echo "Use of this script is only permitted on systems which you have been granted" echo "legal permission to perform a security assessment of. Apart from this " echo "condition the GPL v2 applies." echo echo "Search the output for the word 'WARNING'. If you don't see it then this" echo "script didn't find any problems." echo } banner () { echo "Starting unix-privesc-check v$VERSION ( http://pentestmonkey.net/tools/unix-privesc-check )" echo echo "This script checks file permissions and other settings that could allow" echo "local users to escalate privileges." echo echo "Use of this script is only permitted on systems which you have been granted" echo "legal permission to perform a security assessment of. Apart from this " echo "condition the GPL v2 applies." echo echo "Search the output below for the word 'WARNING'. If you don't see it then" echo "this script didn't find any problems." echo } MODE=$1 if [ ! "$MODE" = "standard" ] && [ ! "$MODE" = "detailed" ]; then usage exit 0 fi # Parse any full paths from $1 (config files, progs, dirs). # Check the permissions on each of these. check_called_programs () { CCP_MESSAGE_STACK=$1 CCP_FILE=$2 CCP_USER=$3 CCP_PATH=$4 # optional # Check the perms of the supplied file regardless # The caller doesn't want to have to call check_perms as well as check_called_programs check_perms "$CCP_MESSAGE_STACK" "$CCP_FILE" "$CCP_USER" "$CCP_PATH" # Skip the slow check if we're in quick mode if [ "$MODE" = "standard" ]; then return 0; fi # Check if file is text or not IS_TEXT=`file "$CCP_FILE" | grep -i text` IS_DYNBIN=`file "$CCP_FILE" | grep -i 'dynamically linked'` # Process shell scripts (would also work on config files that reference other files) if [ ! -z "$IS_TEXT" ]; then # Parse full paths from file - ignoring commented lines CALLED_FILES=`grep -v '^#' "$CCP_FILE" | sed -e 's/^[^\/]*//' -e 's/["'\'':}$]/\x0a/g' | grep '/' | sed -e 's/[ \*].*//' | grep '^/[a-zA-Z0-9_/-]*$' | sort -u` for CALLED_FILE in $CALLED_FILES; do # echo "$CCP_FILE contains a reference to $CALLED_FILE. Checking perms." check_perms "$CCP_MESSAGE_STACK $CCP_FILE contains the string $CALLED_FILE." "$CALLED_FILE" "$CCP_USER" "$CCP_PATH" done else # Process dynamically linked binaries if [ ! -z "$IS_DYNBIN" ]; then CALLED_FILES=`ldd "$CCP_FILE" 2>/dev/null | grep '/' | sed 's/[^\/]*\//\//' | cut -f 1 -d ' '` for CALLED_FILE in $CALLED_FILES; do check_perms "$CCP_MESSAGE_STACK $CCP_FILE uses the library $CALLED_FILE." "$CALLED_FILE" "$CCP_USER" "$CCP_PATH" done # Strings binary to look for hard-coded config files # or other programs that might be called. for CALLED_FILE in `strings "$CCP_FILE" | sed -e 's/^[^\/]*//' -e 's/["'\'':}$]/\x0a/g' | grep '/' | sed -e 's/[ \*].*//' | grep '^/[a-zA-Z0-9_/-]*$' | sort -u`; do check_perms "$CCP_MESSAGE_STACK $CCP_FILE contains the string $CALLED_FILE." "$CALLED_FILE" "$CCP_USER" "$CCP_PATH" done fi fi } # Parse any full paths from $1 (config files, progs, dirs). # Check the permissions on each of these. check_called_programs_suid () { CCP_FILE=$1 CCP_PATH=$2 # optional get_owner $CCP_FILE; CCP_USER=$GET_OWNER_RETURN CCP_MESSAGE_STACK="$CCP_FILE is SUID $CCP_USER." LS=`ls -l $CCP_FILE` echo "Checking SUID-$CCP_USER program $CCP_FILE: $LS" # Don't check perms of executable itself # check_perms "$CCP_MESSAGE_STACK" "$CCP_FILE" "$CCP_USER" "$CCP_PATH" # Check if file is text or not IS_TEXT=`file "$CCP_FILE" | grep -i text` IS_DYNBIN=`file "$CCP_FILE" | grep -i 'dynamically linked'` # Process shell scripts (would also work on config files that reference other files) if [ ! -z "$IS_TEXT" ]; then # Skip the slow check if we're in quick mode if [ "$MODE" = "standard" ]; then return 0; fi # Parse full paths from file - ignoring commented lines CALLED_FILES=`grep -v '^#' "$CCP_FILE" | sed -e 's/^[^\/]*//' -e 's/["'\'':}$]/\x0a/g' | grep '/' | sed -e 's/[ \*].*//' | grep '^/[a-zA-Z0-9_/-]*$' | sort -u` for CALLED_FILE in $CALLED_FILES; do # echo "$CCP_FILE contains a reference to $CALLED_FILE. Checking perms." check_perms "$CCP_MESSAGE_STACK $CCP_FILE contains the string $CALLED_FILE." "$CALLED_FILE" "$CCP_USER" "$CCP_PATH" done else # Process dynamically linked binaries if [ ! -z "$IS_DYNBIN" ]; then CALLED_FILES=`ldd "$CCP_FILE" 2>/dev/null | grep '/' | sed 's/[^\/]*\//\//' | cut -f 1 -d ' '` for CALLED_FILE in $CALLED_FILES; do check_perms "$CCP_MESSAGE_STACK $CCP_FILE uses the library $CALLED_FILE." "$CALLED_FILE" "$CCP_USER" "$CCP_PATH" done # Skip the slow check if we're in quick mode if [ "$MODE" = "standard" ]; then return 0; fi # Strings binary to look for hard-coded config files # or other programs that might be called. for CALLED_FILE in `strings "$CCP_FILE" | sed -e 's/^[^\/]*//' -e 's/["'\'':}$]/\x0a/g' | grep '/' | sed -e 's/[ \*].*//' | grep '^/[a-zA-Z0-9_/-]*$' | sort -u`; do check_perms "$CCP_MESSAGE_STACK $CCP_FILE contains the string $CALLED_FILE." "$CALLED_FILE" "$CCP_USER" "$CCP_PATH" done fi fi } # Check if $1 can be changed by users who are not $2 check_perms () { CP_MESSAGE_STACK=$1 CHECK_PERMS_FILE=$2 CHECK_PERMS_USER=$3 CHECK_PERMS_PATH=$4 # optional if [ ! -f "$CHECK_PERMS_FILE" ] && [ ! -d "$CHECK_PERMS_FILE" ] && [ ! -b "$CHECK_PERMS_FILE" ]; then CHECK_PERMS_FOUND=0 if [ ! -z "$CHECK_PERMS_PATH" ]; then # Look for it in the supplied path for DIR in `echo "$CHECK_PERMS_PATH" | sed 's/:/ /g'`; do if [ -f "$DIR/$CHECK_PERMS_FILE" ]; then CHECK_PERMS_FOUND=1 CHECK_PERMS_FILE="$DIR/$CHECK_PERMS_FILE" break fi done fi #if [ "$CHECK_PERMS_FOUND" = "0" ]; then # echo "ERROR: File $CHECK_PERMS_FILE doesn't exist. Checking parent path anyway." # # return 0 # fi fi C=`echo "$CHECK_PERMS_FILE" | cut -c 1` if [ ! "$C" = "/" ]; then echo "ERROR: Can't find absolute path for $CHECK_PERMS_FILE. Skipping." return 0 fi echo " Checking if anyone except $CHECK_PERMS_USER can change $CHECK_PERMS_FILE" while [ -n "$CHECK_PERMS_FILE" ]; do perms_secure "$CP_MESSAGE_STACK" $CHECK_PERMS_FILE $CHECK_PERMS_USER CHECK_PERMS_FILE=`echo $CHECK_PERMS_FILE | sed 's/\/[^\/]*$//'` done } # Check if $1 can be read by users who are not $2 check_read_perms () { CP_MESSAGE_STACK=$1 CHECK_PERMS_FILE=$2 CHECK_PERMS_USER=$3 if [ ! -f "$CHECK_PERMS_FILE" ] && [ ! -b "$CHECK_PERMS_FILE" ]; then echo "ERROR: File $CHECK_PERMS_FILE doesn't exist" return 0 fi echo " Checking if anyone except $CHECK_PERMS_USER can read file $CHECK_PERMS_FILE" perms_secure_read "$CP_MESSAGE_STACK" "$CHECK_PERMS_FILE" "$CHECK_PERMS_USER" } perms_secure_read () { PS_MESSAGE_STACK=$1 PERMS_SECURE_FILE=$2 PERMS_SECURE_USER=$3 if [ ! -b "$PERMS_SECURE_FILE" ] && [ ! -f "$PERMS_SECURE_FILE" ] && [ ! -d "$PERMS_SECURE_FILE" ]; then echo "ERROR: No such file or directory: $PERMS_SECURE_FILE. Skipping." return 0 fi # Check if owner is different (but ignore root ownership, that's OK) only_user_can_read "$PS_MESSAGE_STACK" $PERMS_SECURE_FILE $PERMS_SECURE_USER # Check group read perm (but ignore root group, that's OK) group_can_read "$PS_MESSAGE_STACK" $PERMS_SECURE_FILE $PERMS_SECURE_USER # Check world read perm world_can_read "$PS_MESSAGE_STACK" $PERMS_SECURE_FILE } perms_secure () { PS_MESSAGE_STACK=$1 PERMS_SECURE_FILE=$2 PERMS_SECURE_USER=$3 if [ ! -d "$PERMS_SECURE_FILE" ] && [ ! -f "$PERMS_SECURE_FILE" ] && [ ! -b "$PERMS_SECURE_FILE" ]; then # echo "ERROR: No such file or directory: $PERMS_SECURE_FILE. Skipping." return 0 fi # Check if owner is different (but ignore root ownership, that's OK) only_user_can_write "$PS_MESSAGE_STACK" $PERMS_SECURE_FILE $PERMS_SECURE_USER # Check group write perm (but ignore root group, that's OK) group_can_write "$PS_MESSAGE_STACK" $PERMS_SECURE_FILE $PERMS_SECURE_USER # Check world write perm world_can_write "$PS_MESSAGE_STACK" $PERMS_SECURE_FILE } only_user_can_write () { O_MESSAGE_STACK=$1 O_FILE=$2 O_USER=$3 # We just need to check the owner really as the owner # can always grant themselves write access get_owner $O_FILE; O_FILE_USER=$GET_OWNER_RETURN if [ ! "$O_USER" = "$O_FILE_USER" ] && [ ! "$O_FILE_USER" = "root" ]; then echo "WARNING: $O_MESSAGE_STACK The user $O_FILE_USER can write to $O_FILE" fi } group_can_write () { O_MESSAGE_STACK=$1 O_FILE=$2 O_USER=$3 # ignore group write access $3 is only member of group get_group $O_FILE; O_FILE_GROUP=$GET_GROUP_RETURN P=`ls -lLd $O_FILE | cut -c 6` if [ "$P" = "w" ] && [ ! "$O_GROUP" = "root" ]; then # check the group actually has some members other than $O_USER group_has_other_members "$O_FILE_GROUP" "$O_USER"; # sets OTHER_MEMBERS to 1 or 0 if [ "$OTHER_MEMBERS" = "1" ]; then echo "WARNING: $O_MESSAGE_STACK The group $O_FILE_GROUP can write to $O_FILE" fi fi } group_has_other_members () { G_GROUP=$1 G_USER=$2 # If LDAP/NIS is being used this script can't check group memberships # we therefore assume the worst. if [ "$EXT_AUTH" = 1 ]; then OTHER_MEMBERS=1 return 1 fi GROUP_LINE=`grep "^$G_GROUP:" /etc/group` MEMBERS=`echo "$GROUP_LINE" | cut -f 4 -d : | sed 's/,/ /g'` GID=`echo "$GROUP_LINE" | cut -f 3 -d :` EXTRA_MEMBERS=`grep "^[^:]*:[^:]*:[0-9]*:$GID:" /etc/passwd | cut -f 1 -d : | xargs echo` for M in $MEMBERS; do if [ ! "$M" = "$G_USER" ] && [ ! "$M" = "root" ]; then OTHER_MEMBERS=1 return 1 fi done for M in $EXTRA_MEMBERS; do if [ ! "$M" = "$G_USER" ] && [ ! "$M" = "root" ]; then OTHER_MEMBERS=1 return 1 fi done OTHER_MEMBERS=0 return 0 } world_can_write () { O_MESSAGE_STACK=$1 O_FILE=$2 P=`ls -lLd $O_FILE | cut -c 9` S=`ls -lLd $O_FILE | cut -c 10` if [ "$P" = "w" ]; then if [ "$S" = "t" ]; then echo "WARNING: $O_MESSAGE_STACK World write is set for $O_FILE (but sticky bit set)" else echo "WARNING: $O_MESSAGE_STACK World write is set for $O_FILE" fi fi } only_user_can_read () { O_MESSAGE_STACK=$1 O_FILE=$2 O_USER=$3 # We just need to check the owner really as the owner # can always grant themselves read access get_owner $O_FILE; O_FILE_USER=$GET_OWNER_RETURN if [ ! "$O_USER" = "$O_FILE_USER" ] && [ ! "$O_FILE_USER" = "root" ]; then echo "WARNING: $O_MESSAGE_STACK The user $O_FILE_USER can read $O_FILE" fi } group_can_read () { O_MESSAGE_STACK=$1 O_FILE=$2 O_USER=$3 get_group $O_FILE; O_FILE_GROUP=$GET_GROUP_RETURN P=`ls -lLd $O_FILE | cut -c 5` if [ "$P" = "r" ] && [ ! "$O_GROUP" = "root" ]; then # check the group actually has some members other than $O_USER group_has_other_members "$O_FILE_GROUP" "$O_USER"; # sets OTHER_MEMBERS to 1 or 0 if [ "$OTHER_MEMBERS" = "1" ]; then echo "WARNING: $O_MESSAGE_STACK The group $O_FILE_GROUP can read $O_FILE" fi fi } world_can_read () { O_MESSAGE_STACK=$1 O_FILE=$2 P=`ls -lLd $O_FILE | cut -c 8` if [ "$P" = "w" ]; then echo "WARNING: $O_MESSAGE_STACK World read is set for $O_FILE" fi } section () { echo echo '############################################' echo $1 echo '############################################' } # Guess OS if [ -x /usr/bin/showrev ]; then OS="solaris" SHADOW="/etc/shadow" elif [ -x /usr/sbin/sam -o -x /usr/bin/sam ]; then OS="hpux" SHADOW="/etc/shadow" elif [ -f /etc/master.passwd ]; then OS="bsd" SHADOW="/etc/master.passwd" else OS="linux" SHADOW="/etc/shadow" fi echo "Assuming the OS is: $OS" CONFIG_FILES="$CONFIG_FILES $SHADOW" # Set path so we can access usual directories. HPUX and some linuxes don't have sbin in the path. PATH=$PATH:/usr/bin:/bin:/sbin:/usr/sbin; export PATH # Check dependent programs are installed # Assume "which" is installed! PROGS="ls awk grep cat mount xargs file ldd strings" for PROG in $PROGS; do which $PROG 2>&1 > /dev/null if [ ! $? = "0" ]; then echo "ERROR: Dependend program '$PROG' is mising. Can't run. Sorry!" exit 1 fi done banner section "Recording hostname" hostname section "Recording uname" uname -a section "Recording Interface IP addresses" if [ $OS = 'hpux' ]; then for IFACE in `lanscan | grep x | awk '{print $5}' 2>/dev/null`; do ifconfig $IFACE 2>/dev/null done else ifconfig -a fi section "Checking if external authentication is allowed in /etc/passwd" FLAG=`grep '^+:' /etc/passwd` if [ -n "$FLAG" ]; then echo "WARNING: /etc/passwd allows external authentcation:" grep '^+:' /etc/passwd EXT_AUTH=1 else echo "No +:... line found in /etc/passwd" fi section "Checking nsswitch.conf for addition authentication methods" if [ -r "/etc/nsswitch.conf" ]; then NIS=`grep '^passwd' /etc/nsswitch.conf | grep 'nis'` if [ -n "$NIS" ]; then echo "WARNING: NIS is used for authentication on this system" EXT_AUTH=1 fi LDAP=`grep '^passwd' /etc/nsswitch.conf | grep 'ldap'` if [ -n "$LDAP" ]; then echo "WARNING: LDAP is used for authentication on this system" EXT_AUTH=1 fi if [ -z "$NIS" ] && [ -z "$LDAP" ]; then echo "Neither LDAP nor NIS are used for authentication" fi else echo "ERROR: File /etc/nsswitch.conf isn't readable. Skipping checks." fi # Check important config files aren't writable section "Checking for writable config files" for FILE in $CONFIG_FILES; do if [ -f "$FILE" ]; then check_perms "$FILE is a critical config file." "$FILE" root fi done section "Checking if $SHADOW is readable" check_read_perms "/etc/shadow holds authentication data" $SHADOW root section "Checking for password hashes in /etc/passwd" FLAG=`grep -v '^[^:]*:[x\*]*:' /etc/passwd | grep -v '^#'` if [ -n "$FLAG" ]; then echo "WARNING: There seem to be some password hashes in /etc/passwd" grep -v '^[^:]*:[x\*]*:' /etc/passwd | grep -v '^#' EXT_AUTH=1 else echo "No password hashes found in /etc/passwd" fi section "Checking account settings" # Check for something nasty like r00t::0:0::/:/bin/sh in /etc/passwd # We only need read access to /etc/passwd to be able to check this. if [ -r "/etc/passwd" ]; then OPEN=`grep "^[^:][^:]*::" /etc/passwd | cut -f 1 -d ":"` if [ -n "$OPEN" ]; then echo "WARNING: The following accounts have no password:" grep "^[^:][^:]*::" /etc/passwd | cut -f 1 -d ":" fi fi if [ -r "$SHADOW" ]; then echo "Checking for accounts with no passwords" if [ "$OS" = "linux" ]; then passwd -S -a | while read LINE do USER=`echo "$LINE" | awk '{print $1}'` STATUS=`echo "$LINE" | awk '{print $2}'` if [ "$STATUS" = "NP" ]; then echo "WARNING: User $USER doesn't have a password" fi done elif [ "$OS" = "solaris" ]; then passwd -s -a | while read LINE do USER=`echo "$LINE" | awk '{print $1}'` STATUS=`echo "$LINE" | awk '{print $2}'` if [ "$STATUS" = "NP" ]; then echo "WARNING: User $USER doesn't have a password" fi done fi else echo "File $SHADOW isn't readable. Skipping some checks." fi section "Checking library directories from /etc/ld.so.conf" if [ -f "/etc/ld.so.conf" ] && [ -r "/etc/ld.so.conf" ]; then for DIR in `grep '^/' /etc/ld.so.conf`; do check_perms "$DIR is in /etc/ld.so.conf." $DIR root done #FILES=`grep '^include' /etc/ld.so.conf | sed 's/^include *//'` #if [ ! -z "$FILES" ]; then # for DIR in `echo $FILES | xargs cat | sort -u`; do # done #fi else echo "File /etc/ld.so.conf not present. Skipping checks." fi # Check sudoers if we have permission - needs root normally section "Checking sudo configuration" if [ -f "/etc/sudoers" ] && [ -r "/etc/sudoers" ]; then echo ----------------- echo "Checking if sudo is configured" SUDO_USERS=`grep -v '^#' /etc/sudoers | grep -v '^[ \t]*$' | grep -v '^[ \t]*Default' | grep =` if [ ! -z "$SUDO_USERS" ]; then echo "WARNING: Sudo is configured. Manually check nothing unsafe is allowed:" grep -v '^#' /etc/sudoers | grep -v '^[ \t]*$' | grep = | grep -v '^[ \t]*Default' fi echo ----------------- echo "Checking sudo users need a password" SUDO_NOPASSWD=`grep -v '^#' /etc/sudoers | grep -v '^[ \t]*$' | grep NOPASSWD` if [ ! -z "$SUDO_NOPASSWD" ]; then echo "WARNING: Some users can use sudo without a password:" grep -v '^#' /etc/sudoers | grep -v '^[ \t]*$' | grep NOPASSWD fi else echo "File /etc/sudoers not present. Skipping checks." fi section "Checking permissions on swap file(s)" for SWAP in `swapon -s | grep -v '^Filename' | cut -f 1 -d ' '`; do check_perms "$SWAP is used for swap space." $SWAP root check_read_perms "$SWAP is used for swap space." $SWAP root done section "Checking programs run from inittab" if [ -f "/etc/inittab" ] && [ -r "/etc/inittab" ]; then for FILE in `cat /etc/inittab | grep : | grep -v '^#' | cut -f 4 -d : | grep '/' | cut -f 1 -d ' ' | sort -u`; do check_called_programs "$FILE is run from /etc/inittab as root." $FILE root done else echo "File /etc/inittab not present. Skipping checks." fi section "Checking postgres trust relationships" for DIR in $PGDIRS; do if [ -d "$DIR" ] && [ -r "$DIR/pg_hba.conf" ]; then grep -v '^#' "$DIR/pg_hba.conf" | grep -v '^[ \t]*$' | while read LINE do AUTH=`echo "$LINE" | awk '{print $NF}'` if [ "$AUTH" = "trust" ]; then PGTRUST=1 echo "WARNING: Postgres trust configured in $DIR/pg_hba.conf: $LINE" fi done fi done PGVER1=`psql -U postgres template1 -c 'select version()' 2>/dev/null | grep version` if [ -n "$PGVER1" ]; then PGTRUST=1 echo "WARNING: Can connect to local postgres database as \"postgres\" without a password" fi PGVER2=`psql -U pgsql template1 -c 'select version()' 2>/dev/null | grep version` if [ -n "$PGVER2" ]; then PGTRUST=1 echo "WARNING: Can connect to local postgres database as \"pgsql\" without a password" fi if [ -z "$PGTRUST" ]; then echo "No postgres trusts detected" fi # Check device files for mounted file systems are secure # cat /proc/mounts | while read LINE # Doesn't work so well when LVM is used - need to be root section "Checking permissions on device files for mounted partitions" if [ "$OS" = "linux" ]; then mount | while read LINE do DEVICE=`echo "$LINE" | awk '{print $1}'` FS=`echo "$LINE" | awk '{print $5}'` if [ "$FS" = "ext2" ] || [ "$FS" = "ext3" ] ||[ "$FS" = "reiserfs" ]; then echo "Checking device $DEVICE" check_perms "$DEVICE is a mounted file system." $DEVICE root fi done elif [ "$OS" = "bsd" ]; then mount | grep ufs | while read LINE do DEVICE=`echo "$LINE" | awk '{print $1}'` echo "Checking device $DEVICE" check_perms "$DEVICE is a mounted file system." $DEVICE root done elif [ "$OS" = "solaris" ]; then mount | grep xattr | while read LINE do DEVICE=`echo "$LINE" | awk '{print $3}'` if [ ! "$DEVICE" = "swap" ]; then echo "Checking device $DEVICE" check_perms "$DEVICE is a mounted file system." $DEVICE root fi done elif [ "$OS" = "hpux" ]; then mount | while read LINE do DEVICE=`echo "$LINE" | awk '{print $3}'` C=`echo $DEVICE | cut -c 1` if [ "$C" = "/" ]; then echo "Checking device $DEVICE" check_perms "$DEVICE is a mounted file system." $DEVICE root fi done NFS=`mount | grep NFS` if [ -n "$NFS" ]; then echo "WARNING: This system is an NFS client. Check for nosuid and nodev options." mount | grep NFS fi fi # Check cron jobs if they're readable # TODO check that cron is actually running section "Checking cron job programs aren't writable (/etc/crontab)" CRONDIRS="" if [ -f "/etc/crontab" ] && [ -r "/etc/crontab" ]; then MYPATH=`grep '^PATH=' /etc/crontab | cut -f 2 -d = ` echo Crontab path is $MYPATH # Check if /etc/cron.(hourly|daily|weekly|monthly) are being used CRONDIRS=`grep -v '^#' /etc/crontab | grep -v '^[ \t]*$' | grep '[ \t][^ \t][^ \t]*[ \t][ \t]*' | grep run-crons` # Process run-parts grep -v '^#' /etc/crontab | grep -v '^[ \t]*$' | grep '[ \t][^ \t][^ \t]*[ \t][ \t]*' | grep run-parts | while read LINE do echo "Processing crontab run-parts entry: $LINE" USER=`echo "$LINE" | awk '{print $6}'` DIR=`echo "$LINE" | sed 's/.*run-parts[^()&|;\/]*\(\/[^ ]*\).*/\1/'` check_perms "$DIR holds cron jobs which are run as $USER." "$DIR" "$USER" if [ -d "$DIR" ]; then echo " Checking directory: $DIR" for FILE in $DIR/*; do FILENAME=`echo "$FILE" | sed 's/.*\///'` if [ "$FILENAME" = "*" ]; then echo " No files in this directory." continue fi check_called_programs "$FILE is run by cron as $USER." "$FILE" "$USER" done fi done # TODO bsd'd periodic: # 1 3 * * * root periodic daily # 15 4 * * 6 root periodic weekly # 30 5 1 * * root periodic monthly grep -v '^#' /etc/crontab | grep -v '^[ ]*$' | grep '[ ][^ ][^ ]*[ ][ ]*' | while read LINE do echo "Processing crontab entry: $LINE" USER=`echo "$LINE" | awk '{print $6}'` PROG=`echo "$LINE" | awk '{print $7}'` check_called_programs "$PROG is run from crontab as $USER." $PROG $USER $MYPATH done else echo "File /etc/crontab not present. Skipping checks." fi # Do this if run-crons is run from /etc/crontab if [ -n "$CRONDIRS" ]; then USER=`echo "$CRONDIRS" | awk '{print $6}'` section "Checking /etc/cron.(hourly|daily|weekly|monthly)" for DIR in hourly daily weekly monthly; do if [ -d "/etc/cron.$DIR" ]; then echo " Checking directory: /etc/cron.$DIR" for FILE in /etc/cron.$DIR/*; do FILENAME=`echo "$FILE" | sed 's/.*\///'` if [ "$FILENAME" = "*" ]; then echo "No files in this directory." continue fi check_called_programs "$FILE is run via cron as $USER." "$FILE" $USER done fi done fi section "Checking cron job programs aren't writable (/var/spool/cron/crontabs)" if [ -d "/var/spool/cron/crontabs" ]; then for FILE in /var/spool/cron/crontabs/*; do USER=`echo "$FILE" | sed 's/^.*\///'` if [ "$USER" = "*" ]; then echo "No user crontabs found in /var/spool/cron/crontabs. Skipping checks." continue fi echo "Processing crontab for $USER: $FILE" if [ -r "$FILE" ]; then MYPATH=`grep '^PATH=' "$FILE" | cut -f 2 -d = ` if [ -n "$MYPATH" ]; then echo Crontab path is $MYPATH fi grep -v '^#' "$FILE" | grep -v '^[ \t]*$' | grep '[ \t][^ \t][^ \t]*[ \t][ \t]*' | while read LINE do echo "Processing crontab entry: $LINE" PROG=`echo "$LINE" | awk '{print $6}'` check_called_programs "$PROG is run via cron as $USER." "$PROG" $USER done else echo "ERROR: Can't read file $FILE" fi done else echo "Directory /var/spool/cron/crontabs is not present. Skipping checks." fi section "Checking cron job programs aren't writable (/var/spool/cron/tabs)" if [ -d "/var/spool/cron/tabs" ]; then for FILE in /var/spool/cron/tabs/*; do USER=`echo "$FILE" | sed 's/^.*\///'` if [ "$USER" = "*" ]; then echo "No user crontabs found in /var/spool/cron/crontabs. Skipping checks." continue fi echo "Processing crontab for $USER: $FILE" if [ -r "$FILE" ]; then MYPATH=`grep '^PATH=' "$FILE" | cut -f 2 -d = ` if [ -n "$MYPATH" ]; then echo Crontab path is $MYPATH fi grep -v '^#' "$FILE" | grep -v '^[ \t]*$' | grep '[ \t][^ \t][^ \t]*[ \t][ \t]*' | while read LINE do echo "Processing crontab entry: $LINE" PROG=`echo "$LINE" | awk '{print $6}'` check_called_programs "$PROG is run from cron as $USER." $PROG $USER $MYPATH done else echo "ERROR: Can't read file $FILE" fi done else echo "Directory /var/spool/cron/tabs is not present. Skipping checks." fi # Check programs run from /etc/inetd.conf have secure permissions # TODO: check inetd is actually running section "Checking inetd programs aren't writable" if [ -f /etc/inetd.conf ] && [ -r /etc/inetd.conf ]; then grep -v '^#' /etc/inetd.conf | grep -v '^[ \t]*$' | while read LINE do USER=`echo $LINE | awk '{print $5}'` PROG=`echo $LINE | awk '{print $6}'` # could be tcpwappers ... PROG2=`echo $LINE | awk '{print $7}'` # ... and this is the real prog if [ -z "$PROG" ] || [ "$PROG" = "internal" ]; then # Not calling an external program continue fi echo Processing inetd line: $LINE if [ -f "$PROG" ]; then check_called_programs "$PROG is run from inetd as $USER." $PROG $USER fi if [ -f "$PROG2" ]; then check_called_programs "$PROG is run from inetd as $USER." $PROG2 $USER fi done else echo "File /etc/inetd.conf not present. Skipping checks." fi # Check programs run from /etc/xinetd.d/* # TODO: check xinetd is actually running section "Checking xinetd programs aren't writeable" if [ -d /etc/xinetd.d ]; then for FILE in `grep 'disable[ \t]*=[ \t]*no' /etc/xinetd.d/* | cut -f 1 -d :`; do echo Processing xinetd service file: $FILE PROG=`grep '^[ \t]*server[ \t]*=[ \t]*' $FILE | sed 's/.*server.*=[ \t]*//'` USER=`grep '^[ \t]*user[ \t]*=[ \t]*' $FILE | sed 's/.*user.*=[ \t]*//'` check_called_programs "$PROG is run from xinetd as $USER." $PROG $USER done else echo "Directory /etc/xinetd.d not present. Skipping checks." fi # Check for writable home directories section "Checking home directories aren't writable" cat /etc/passwd | grep -v '^#' | while read LINE do echo Processing /etc/passwd line: $LINE USER=`echo $LINE | cut -f 1 -d :` DIR=`echo $LINE | cut -f 6 -d :` SHELL=`echo $LINE | cut -f 7 -d :` if [ "$SHELL" = "/sbin/nologin" ] || [ "$SHELL" = "/bin/false" ]; then echo " Skipping user $USER. They don't have a shell." else if [ "$DIR" = "/dev/null" ]; then echo " Skipping /dev/null home directory" else check_perms "$DIR is the home directory of $USER." $DIR $USER fi fi done # Check for readable files in home directories section "Checking for readable sensitive files in home directories" cat /etc/passwd | while read LINE do USER=`echo $LINE | cut -f 1 -d :` DIR=`echo $LINE | cut -f 6 -d :` SHELL=`echo $LINE | cut -f 7 -d :` for FILE in $HOME_DIR_FILES; do if [ -f "$DIR/$FILE" ]; then check_read_perms "$DIR/$FILE is in the home directory of $USER." "$DIR/$FILE" $USER fi done done section "Checking SUID programs" if [ "$MODE" = "detailed" ]; then for FILE in `find / -type f -perm -04000 2>/dev/null`; do check_called_programs_suid $FILE done else echo "Skipping checks of SUID programs (it's slow!). Run again in 'detailed' mode." fi # Check for private SSH keys in home directories section "Checking for Private SSH Keys home directories" for HOMEDIR in `cut -f 6 -d : /etc/passwd`; do if [ -d "$HOMEDIR/.ssh" ]; then PRIV_KEYS=`grep -l 'BEGIN [RD]SA PRIVATE KEY' $HOMEDIR/.ssh/* 2>/dev/null` if [ -n "$PRIV_KEYS" ]; then for KEY in $PRIV_KEYS; do ENC_KEY=`grep -l 'ENCRYPTED' "$KEY" 2>/dev/null` if [ -n "$ENC_KEY" ]; then echo "WARNING: Encrypted Private SSH Key Found in $KEY" else echo "WARNING: Unencrypted Private SSH Key Found in $KEY" fi done fi fi done # Check for public SSH keys in home directories section "Checking for Public SSH Keys home directories" for HOMEDIR in `cut -f 6 -d : /etc/passwd`; do if [ -r "$HOMEDIR/.ssh/authorized_keys" ]; then KEYS=`grep '^ssh-' $HOMEDIR/.ssh/authorized_keys 2>/dev/null` if [ -n "$KEYS" ]; then echo "WARNING: Public SSH Key Found in $HOMEDIR/.ssh/authorized_keys" fi fi done # Check for any SSH agents running on the box section "Checking for SSH agents" AGENTS=`ps -ef | grep ssh-agent | grep -v grep` if [ -n "$AGENTS" ]; then echo "WARNING: There are SSH agents running on this system:" ps -ef | grep ssh-agent | grep -v grep # for PID in `ps aux | grep ssh-agent | grep -v grep | awk '{print $2}'`; do for SOCK in `ls /tmp/ssh-*/agent.* 2>/dev/null`; do SSH_AUTH_SOCK=$SOCK; export SSH_AUTH_SOCK AGENT_KEYS=`ssh-add -l | grep -v 'agent has no identities.' 2>/dev/null` if [ -n "$AGENT_KEYS" ]; then echo "WARNING: SSH Agent has keys loaded [SSH_AUTH_SOCK=$SSH_AUTH_SOCK]" ssh-add -l fi done else echo "No SSH agents found" fi # Check for any GPG agents running on the box section "Checking for GPG agents" AGENTS=`ps -ef | grep gpg-agent | grep -v grep` if [ -n "$AGENTS" ]; then echo "WARNING: There are GPG agents running on this system:" ps aux | grep gpg-agent | grep -v grep else echo "No GPG agents found" fi # Check files in /etc/init.d/* can't be modified by non-root users section "Checking startup files (init.d / rc.d) aren't writable" for DIR in /etc/init.d /etc/rc.d /usr/local/etc/rc.d; do if [ -d "$DIR" ]; then for FILE in $DIR/*; do F=`echo "$FILE" | sed 's/^.*\///'` if [ "$F" = "*" ]; then echo "No user startup script found in $DIR. Skipping checks." continue fi echo Processing startup script $FILE check_called_programs "$FILE is run by root at startup." $FILE root done fi done section "Checking if running programs are writable" if [ $OS = "solaris" ]; then # use the output of ps command ps -ef -o user,comm | while read LINE do USER=`echo "$LINE" | awk '{print $1}'` PROG=`echo "$LINE" | awk '{print $2}'` check_called_programs "$PROG is currently running as $USER." "$PROG" "$USER" done elif [ $OS = "bsd" ]; then # use the output of ps command ps aux | while read LINE do USER=`echo "$LINE" | awk '{print $1}'` PROG=`echo "$LINE" | awk '{print $11}'` check_called_programs "$PROG is currently running as $USER." "$PROG" "$USER" done elif [ $OS = "hpux" ]; then # use the output of ps command ps -ef | while read LINE do USER=`echo "$LINE" | awk '{print $1}'` PROG1=`echo "$LINE" | awk '{print $8}'` PROG2=`echo "$LINE" | awk '{print $9}'` if [ -f "$PROG1" ]; then check_called_programs "$PROG is currently running as $USER." "$PROG1" "$USER" fi if [ -f "$PROG2" ]; then check_called_programs "$PROG is currently running as $USER." "$PROG2" "$USER" fi done elif [ $OS = "linux" ]; then # use the /proc file system for PROCDIR in /proc/[0-9]*; do unset PROGPATH PID=`echo $PROCDIR | cut -f 3 -d /` echo ------------------------ echo "PID: $PID" if [ -d "$PROCDIR" ]; then if [ -r "$PROCDIR/exe" ]; then PROGPATH=`ls -l "$PROCDIR/exe" 2>&1 | sed 's/ (deleted)//' | awk '{print $NF}'` else if [ -r "$PROCDIR/cmdline" ]; then P=`cat $PROCDIR/cmdline | tr "\0" = | cut -f 1 -d = | grep '^/'` if [ -z "$P" ]; then echo "ERROR: Can't find full path of running program: "`cat $PROCDIR/cmdline` else PROGPATH=$P fi else echo "ERROR: Can't find full path of running program: "`cat $PROCDIR/cmdline` continue fi fi get_owner $PROCDIR; OWNER=$GET_OWNER_RETURN echo "Owner: $OWNER" else echo "ERROR: Can't find OWNER. Process has gone." continue fi if [ -n "$PROGPATH" ]; then get_owner $PROGPATH; PROGOWNER=$GET_OWNER_RETURN echo "Program path: $PROGPATH" check_called_programs "$PROGPATH is currently running as $OWNER." $PROGPATH $OWNER fi if [ "$MODE" == "detailed" ]; then for FILE in $PROCDIR/fd/*; do F=`echo "$FILE" | sed 's/^.*\///'` if [ "$F" = "*" ]; then continue fi check_perms "$FILE is an open file descriptor for process $PID running as $OWNER." $FILE $OWNER done fi done fi