tiger 1:3.2.3-12.1 / usr / lib / tiger / scripts / check_known

#!/bin/sh
#
#     tiger - A UN*X security checking system
#     Copyright (C) 1993 Douglas Lee Schales, David K. Hess, David R. Safford
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2, or (at your option)
#    any later version.
#
#    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.
#
#     Please see the file `COPYING' for the complete copyright notice.
#
# check_known - 06/14/93
#
# 08/30/2013 jfs Determine properly the kernel version to decide wether to user
# ifconfig (or not) (Debian bug: #708360)
#
# 04/05/2010 jfs Use WC instead of wc and avoid bashisms in script
#  Also, improve the fix introduced in previous version to handle
#  also newlines in files. Reducing the number of printed bad files to 100
#
# 02/26/2010 fgclaramonte  Prevent error messages if there are files 
#  under /lost+found or /*/lost+found containinng
#  spaces in their name. 
#  Also add support in the expressions of ReiserFS-style
#  fsck filenames (nnnn_nnnn) to the more common (#nnnn) type, but
#  not in the case of HP-UX as presumably it lacks Reiser support.
#  (Debian bug 532826)
# 
# 05/20/2006 jfs Use TAIL properly (POSIX 1003.2-1992)
# 06/15/2004 jfs Do not call LS directly with all files but use a for loop
#                (Debian bug #246600)
# 01/15/2004 jfs Do not run the inetd code if inetd_sets is emtpy!
# 11/19/2003 jfs Linux: accurate, per interface, promiscuous mode detection
#                Contributed by unspawn with some changes to make it POSIX
#                correct.
# 10/01/2003 jfs Do not delete passwd files if the Tiger_PasswdFiles is
#                defined, otherwise checks relying on it will break
# 09/19/2003 jfs Fixed deletion of temporary files thanks to a patch
#                provided by Nicolas François 
# 08/14/2003 jfs Added OUTPUTMETHOD to dependancies. Incorporated tests
#                implemented by ARSC (quite a time ago....)
# 08/08/2003 jfs Safe temporary file creation
# 05/01/2003 jfs Removed RM and CC from dependancies
# 04/15/2003 jfs Removed the 'cd' to MAILSPOOL since the CAT of the passlist
#		 will not work if BASEDIR is relative. Fixed the AWK call
#		 (was being made to the wrong file!)
# 07/25/2002 jfs Added a sanity check for password files
# 18/05/2002 jfs Changed cat to $CAT in some calls
# 28/03/2002 jfs Applied some of the changes described by CHANGES.ARSC from 
#              mlk.
# 09/14/2001 ret Added test for promiscous mode in ifconfig
# 09/24/2001 ret Added test for shell (e.g. bin/sh) in inetd.conf
# 14/09/2001 jfs Changed to ls -lan so it can check user's id (otherwise it
#              does not work for long user names) affects only SPOOL check
# 06/06/1993 dls Moved 1's complement check to SunOS 4.x specific
# 04/27/1993 dls "1's complement" check of /bin/login added
#
#-----------------------------------------------------------------------------
# TODO
# - Many exploits run code that make inetd source a different configuration
#   file through the use of the '-s' flag (available in SunOS and OpenBSD)
#   or by directly specifying a configuration file (works in FreeBSD and Linux)
#-----------------------------------------------------------------------------
#
TigerInstallDir="/usr/lib/tiger"

#
# Set default base directory.
# Order or preference:
#      -B option
#      TIGERHOMEDIR environment variable
#      TigerInstallDir installed location
#
basedir=${TIGERHOMEDIR:=$TigerInstallDir}

for parm
do
   case $parm in
   -B) basedir=$2; break;;
   esac
done

#
# Verify that a config file exists there, and if it does
# source it.
#
[ ! -r $basedir/config ] && {
  echo "--ERROR-- [init002e] No 'config' file in \`$basedir'."
  exit 1
}

. $basedir/config

. $BASEDIR/initdefs

#
# If run in test mode (-t) this will verify that all required
# elements are set.
#
[ "$Tiger_TESTMODE" = 'Y' ] && {
  haveallcmds AWK CAT EGREP FIND GET_MOUNTS LS SED SGREP STRINGS TR TAIL HEAD CUT OUTPUTMETHOD RM GEN_INETD_SETS WC || exit 1
  haveallfiles BASEDIR WORKDIR || exit 1
  haveallvars TESTLINK HOSTNAME
  
  echo "--CONFIG-- [init003c] $0: Configuration ok..."
  exit 0
}

#------------------------------------------------------------------------
echo
echo "# Checking for known intrusion signs..."

haveallcmds AWK CAT EGREP FIND GET_MOUNTS LS SED SGREP STRINGS TR TAIL HEAD CUT OUTPUTMETHOD RM GEN_INETD_SETS WC || exit 1
haveallfiles BASEDIR WORKDIR || exit 1

safe_temp "$WORKDIR/login.str.$$" "$WORKDIR/pass.list.$$"
trap 'delete $WORKDIR/login.str.$$ $WORKDIR/pass.list.$$ ; exit 1' 1 2 3 15

{
  haveallcmds IFCONFIG && { 
     # Note: This is Linux specific 
     # (maybe should be moved to systems/Linux/2/check_known)
     [ ! -x "$IP" -o "$OS" != "Linux" ] && message INFO kisXXX "" "Using $IFCONFIG instead of $IP, promiscuous mode detection incomplete. Installing $IP adds libpcap/libnet-based sniffer detection capabilities."

     # Extract kernel major and minor version, only take numbers
     MAJOR_VER=`echo $REV | $CUT -f 1 -d . | $EGREP '^[0-9].*'`
     MINOR_VER=`echo $REV | $CUT -f 2 -d . | $SED -e 's/-.*$//' |  $EGREP '^[0-9].*'`
     # only use ifconfig if 'ip' is not available or if we are in version 2.4 or earlier
     if [ ! -x "$IP" ] || [ -z $MAJOR_VER ] || [ $MAJOR_VER -eq 2 -a $MINOR_VER -lt 4 ]  || [ $MAJOR_VER -lt 2 ]
     then
         echo "# Testing for promiscuous interfaces with $IFCONFIG"
         promisc="`$IFCONFIG -a | $GREP -i PROMISC`"
         [ -n "$promisc" ] && message ALERT kis013a "" "One of the interfaces is set for promiscuous mode"
     else
         echo "# Testing for promiscuous interfaces with $IP"
         $IP link show |
	 $EGREP '^[0-9].*PROMISC' |
	 # Alternative:
         # $IP link show|
	 # $AWK '/^[0-9].*UP/{printf "Device \t%s promisc. \t%s\n", $2, $3}'
         while read number intf flags other
         do
            message ALERT kis013a "" "Interface $intf set for promiscuous mode"
         done
     fi
  }
  
  echo "# Testing for backdoors in inetd.conf"
  inetd_sets=`$GEN_INETD_SETS`
  if [ -n "$inetd_sets" ] 
  then
  # TODO inetd_sets should be appended with any non-option which 
  # has been fed to the current running inetd (use PS to locate it)
  shcase='/bin/sh|/bin/csh|/bin/bash|/bin/tcsh|/bin/ksh'
  [ -n "$ETCSHELLS" -a -s "$ETCSHELLS" ] && {
    shells=`$GREP -v '^#' $ETCSHELLS`
    shcase=`echo $shells | $TR ' ' '|'`
  }
  backdoor="`$EGREP $shcase $inetd_sets`"
  if [ -n "$backdoor" ]; then
     message ALERT kis014a "" "There is a shell defined in inetd.conf, the backdoor line is: '$backdoor'"
  fi
  delete $inetd_sets $inetd_sets.src
  fi # Of if $inetd_sets

  file_list="/usr/spool/uucppublic/.hushlogin /usr/spool/secretmail/.l /tmp/a
/usr/spool/secretmail/.log /usr/spool/secretmail/.tty
/usr/spool/secretmail/.lock /usr/tmp/.log /usr/spool/uucp/.sys
/usr/uucp/.sys /var/crash/... /usr/etc/.getwd /var/crash/.getwd /usr/kvm/... /dev/.tty /dev/.test"

  for file in $file_list
  do
    [ -s "$file" ] && {
      if [ -d "$file" ]; then
	message ALERT kis001a "" "$file is a directory."
	$LS -AlR "$file"
	echo
      else 
	message ALERT kis002a "" "$file is not zero-length."
	$LS -l "$file"
	echo
      fi
    }
  done

  haveallcmds EGREP FIND && {
    for serverdir in /tmp/.X11-unix /tmp/.NeWS-unix
    do
      [ -d "$serverdir" ] && {
	nonsocket=`$FIND $serverdir/ ! -type s -a ! -type p -print |
	$EGREP -v '^'"$serverdir"'/$'`

	[ -n "$nonsocket" ] && {
	  message ALERT kis003a "" "$serverdir contains files other than window server sockets:"
	  $LS -alR "$serverdir"
  	  echo
	}
      }
    done
  }
  
  haveallcmds GET_MOUNTS AWK FIND SED WC TR && {
    $GET_MOUNTS local |
    $AWK '{
      if($1 == "/")
        print "/lost+found";
      else
        print $1 "/lost+found";
    }' |
    while read dir
    do
      [ -d "$dir" -a -r "$dir" ] && {
	cd "$dir"
        # List files we have to alert on.
        # Be careful to handle strange files (with spaces or newline
        # characters). To do this:
        # We first list them, then convert newlines to '~' and then
        # 1) remove the first './', replace '~./' with newlines and
        # replace the last '~' with a newline. Remaining newlines are located
        # within the file name and are left as '~'
	alertfiles="`$FIND . -name . -fprintf /dev/null '' -o \( -name '#[0-9]*' -o -name '[0-9]*_[0-9]*' \) -prune -o -print | $TR '\n' '~' | $SED 's%^./%%; s%~./%\n%g; s%~$%\n%'`"
	# On HP-UX change to:
	#alertfiles="`$FIND . \( -name . -o -name .fsadm \) -fprintf /dev/null '' -o -name '#[0-9]*' -prune -o -print | $TR '\n' '~' | $SED 's%^./%%; s%~./%\n%g; s%~$%\n%'`"s%^./%%'`"
	if [ -n "$alertfiles" ]; then
	  message WARN kis004w "" "$dir contains possible non-fsck files:"
	  # If there are very many non-fsck files, don't list them
	  # and just provide the raw count.
	  filecount="`echo "$alertfiles" | $WC -l`"
	  if [ $filecount -lt 100 ]; then
	    echo "$alertfiles" | while read file; do
	  	  $LS -ld "$file"
	    done
	  else
	    echo "($filecount files)"
	  fi
	  echo
	else
	  filecount="`$LS -a | $WC -l`"
	  if [ $filecount -gt 2 ]; then
	    message WARN kis004w "Files: ${filecount} file(s)" "$dir is not empty:"
	  fi
	fi
      }
    done
  }

  haveallcmds STRINGS SGREP && {
    $STRINGS - /bin/login > $WORKDIR/login.str.$$
    $SGREP 'back' $WORKDIR/login.str.$$ && {
      message ALERT kis005a "" "/bin/login may contain backdoor login"
    }
    $SGREP 'BACK' $WORKDIR/login.str.$$ && {
      message ALERT kis005a "" "/bin/login may contain backdoor login"
    }
    delete $WORKDIR/login.str.$$
  }

  [ -n "$TESTSUID" -a $TESTEXEC "$TESTSUID" ] && {
    $TESTSUID ||
    message ALERT kis007a "" "The setuid(2) system call is compromised."
  }

  haveallcmds GEN_PASSWD_SETS GREP CUT AWK LS TAIL HEAD &&
  haveallfiles BASEDIR MAILSPOOL WORKDIR && (
    echo
    echo "# Performing check of files in system mail spool..."


     if [ -n "$Tiger_PasswdFiles" ]; then
      [ -f $Tiger_PasswdFiles ] && $CAT "$Tiger_PasswdFiles" > $WORKDIR/pass.list.$$
     else
      $GEN_PASSWD_SETS $WORKDIR/pass.list.$$
     fi

# Added -n for numeric uids, jfs
    $LS -anl $MAILSPOOL/  |
    $TAIL -n +2 |
    $AWK '{print $3, $NF}' |
    while read uid file
    do
    
    # TODO: the current scheme does not work correctly  in all cases 
    # if there is more that one user with the same UID 
    # (the ^+ is there to prevent confusing
    # NIS records) and the $HEAD -1 just takes the first one...
    # (this errors are introduced due to the numeric checks instead of name
    # checks.... oh well...)
     owner=""
     for passwd_set in `$CAT $WORKDIR/pass.list.$$`
     do
      [ -z "$owner" ] && 
#	 owner=`$GREP :$uid: $passwd_set | $GREP -v "^+" | $CUT -f 1 -d : |$HEAD -1`
	 owner=`$AWK -F: '$3 ~ /^'$uid'$/ { print $1 }' $passwd_set | $HEAD -1`
     done 

     # If the user is not found in the password file
     if [ -n "$owner" ] ; then
	     [ "$file" != '.' -a "$file" != '..' -a "$file" != ':saved' -a "$owner" != "$file" ] &&
	     message WARN kis008w "" "File \"$file\" in the mail spool, owned by \"$owner\"."
     else
	     [ "$file" != '.' -a "$file" != '..' ] &&
	     message WARN kis010w "" "File \"$file\" in the mail spool does not belong to a valid user (belongs to uid \"$uid\")."
     fi

    done # of the while read

    if [ -f $WORKDIR/pass.list.$$ ] ; then
    	if [ -z "$Tiger_PasswdFiles" ] ; then
 	     	for passwd_set in `$CAT $WORKDIR/pass.list.$$`; do
      			delete $passwd_set $passwd_set.src 
      		done
	fi
	delete $WORKDIR/pass.list.$$
    fi
  )
} |
$OUTPUTMETHOD
#
exit 0