NetBSD/etc/security
lukem 89fa41e9da - correct use of generated temporary files.
- clean up comments and generated output.
- clean up $SECUREDIR if SIGINT or SIGQUIT received.
- .rhosts may have to be world readable in NFS environments, so allow it to be.
- update list of disks to check for reasonable permissions
- don't show differences in /etc/master.passwd, as the encrypted strings may
  be sent. From reading comments earlier in the script, this was the intention
  anyway. Fix from Jim Bernard <jbernard@tater.mines.edu> in [security/3994].
- when checking /etc/ftpusers, skip comment lines and only match full
  usernames.
  XXX: this should be enhanced to check lines of the enhanced ftpusers format.
1997-08-22 09:40:17 +00:00

612 lines
16 KiB
Bash

#!/bin/sh -
#
# $NetBSD: security,v 1.27 1997/08/22 09:40:17 lukem Exp $
# from: @(#)security 8.1 (Berkeley) 6/9/93
#
PATH=/sbin:/usr/sbin:/bin:/usr/bin
umask 077
if [ -s /etc/security.conf ]; then
. /etc/security.conf
fi
SECUREDIR=/tmp/_securedir.$$
if ! mkdir $SECUREDIR; then
echo can not create $SECUREDIR.
exit 1
fi
if ! cd $SECUREDIR; then
echo can not chdir to $SECUREDIR.
exit 1
fi
ERR=secure1.$$
TMP1=secure2.$$
TMP2=secure3.$$
MPUID=secure4.$$
MPPATH=secure5.$$
LIST=secure6.$$
OUTPUT=secure7.$$
trap '/bin/rm -rf $SECUREDIR ; exit 0' 0 2 3
MP=/etc/master.passwd
# these is used several times.
awk -F: '{ print $1 " " $3 }' $MP | sort -k2n > $MPUID
awk -F: '{ print $1 " " $9 }' $MP | sort -k2 > $MPPATH
# Check the master password file syntax.
if [ "$check_passwd" = YES ]; then
awk '
BEGIN {
while ( getline < "/etc/shells" > 0 ) {
if ($LINE ~ /^\#/ || $LINE ~ /^$/ )
continue;
shells[$1]++;
}
FS=":";
}
{
if ($0 ~ /^[ ]*$/) {
printf "Line %d is a blank line.\n", NR;
next;
}
if (NF != 10)
printf "Line %d has the wrong number of fields.\n", NR;
if ($1 !~ /^[A-Za-z0-9]*$/)
printf "Login %s has non-alphanumeric characters.\n",
$1;
if (length($1) > 8)
printf "Login %s has more than 8 characters.\n", $1;
if ($2 == "")
printf "Login %s has no password.\n", $1;
if (length($2) != 13 && $2 != "") {
if ($10 == "" || shells[$10])
printf "Login %s is off but still has a valid shell (%s)\n",
$1, $10;
} else if (! shells[$10])
printf "Login %s does not have a valid shell (%s)\n",
$1, $10;
if ($3 == 0 && $1 != "root" && $1 != "toor")
printf "Login %s has a user id of 0.\n", $1;
if ($3 < 0)
printf "Login %s has a negative user id.\n", $1;
if ($4 < 0)
printf "Login %s has a negative group id.\n", $1;
}' < $MP > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking the $MP file:\n"
cat $OUTPUT
fi
awk -F: '{ print $1 }' $MP | sort | uniq -d > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\n$MP has duplicate user names.\n"
column $OUTPUT
fi
< $MPUID uniq -d -f 1 | awk '{ print $2 }' > $TMP2
if [ -s $TMP2 ] ; then
printf "\n$MP has duplicate user id's.\n"
while read uid; do
grep -w $uid $MPUID
done < $TMP2 | column
fi
fi
# Backup the master password file; a special case, the normal backup
# mechanisms also print out file differences and we don't want to do
# that because this file has encrypted passwords in it.
CUR=/var/backups/`basename $MP`.current
BACK=/var/backups/`basename $MP`.backup
if [ -s $CUR ] ; then
if cmp -s $CUR $MP; then
:
else
cp -p $CUR $BACK
cp -p $MP $CUR
chown root.wheel $CUR
fi
else
cp -p $MP $CUR
chown root.wheel $CUR
fi
# Check the group file syntax.
if [ "$check_group" = YES ]; then
GRP=/etc/group
awk -F: '{
if ($0 ~ /^[ ]*$/) {
printf "Line %d is a blank line.\n", NR;
next;
}
if (NF != 4)
printf "Line %d has the wrong number of fields.\n", NR;
if ($1 !~ /^[A-za-z0-9]*$/)
printf "Group %s has non-alphanumeric characters.\n",
$1;
if (length($1) > 8)
printf "Group %s has more than 8 characters.\n", $1;
if ($3 !~ /[0-9]*/)
printf "Login %s has a negative group id.\n", $1;
}' < $GRP > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking the $GRP file:\n"
cat $OUTPUT
fi
awk -F: '{ print $1 }' $GRP | sort | uniq -d > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\n$GRP has duplicate group names.\n"
column $OUTPUT
fi
fi
# Check for root paths, umask values in startup files.
# The check for the root paths is problematical -- it's likely to fail
# in other environments. Once the shells have been modified to warn
# of '.' in the path, the path tests should go away.
if [ "$check_rootdotfiles" = YES ]; then
cp /dev/null $OUTPUT
rhome=`csh -fc "echo ~root"`
umaskset=no
list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login"
for i in $list ; do
if [ -f $i ] ; then
if egrep umask $i > /dev/null ; then
umaskset=yes
fi
egrep umask $i |
awk '$2 % 100 < 20 \
{ print "\tRoot umask is group writeable" }
$2 % 10 < 2 \
{ print "\tRoot umask is other writeable" }' \
>> $OUTPUT
SAVE_PATH=$PATH
unset PATH
/bin/csh -f -s << end-of-csh > /dev/null 2>&1
source $i
/bin/ls -ldgT \$path > $TMP1
end-of-csh
PATH=$SAVE_PATH
awk '{
if ($10 ~ /^\.$/) {
print "\tThe root path includes .";
next;
}
}
$1 ~ /^d....w/ \
{ print "\tRoot path directory " $10 " is group writeable." } \
$1 ~ /^d.......w/ \
{ print "\tRoot path directory " $10 " is other writeable." }' \
< $TMP1 >> $OUTPUT
fi
done
if [ $umaskset = "no" -o -s $OUTPUT ] ; then
printf "\nChecking root csh paths, umask values:\n$list\n\n"
if [ -s $OUTPUT ]; then
cat $OUTPUT
fi
if [ $umaskset = "no" ] ; then
printf "\tRoot csh startup files do not set the umask.\n"
fi
fi
cp /dev/null $OUTPUT
rhome=/root
umaskset=no
list="/etc/profile ${rhome}/.profile"
for i in $list; do
if [ -f $i ] ; then
if egrep umask $i > /dev/null ; then
umaskset=yes
fi
egrep umask $i |
awk '$2 % 100 < 20 \
{ print "\tRoot umask is group writeable" } \
$2 % 10 < 2 \
{ print "\tRoot umask is other writeable" }' \
>> $OUTPUT
SAVE_PATH=$PATH
unset PATH
/bin/sh << end-of-sh > /dev/null 2>&1
. $i
list=\`echo \$PATH | /usr/bin/sed -e \
's/^:/.:/;s/:$/:./;s/::/:.:/g;s/:/ /g'\`
/bin/ls -ldgT \$list > $TMP1
end-of-sh
PATH=$SAVE_PATH
awk '{
if ($10 ~ /^\.$/) {
print "\tThe root path includes .";
next;
}
}
$1 ~ /^d....w/ \
{ print "\tRoot path directory " $10 " is group writeable." } \
$1 ~ /^d.......w/ \
{ print "\tRoot path directory " $10 " is other writeable." }' \
< $TMP1 >> $OUTPUT
fi
done
if [ $umaskset = "no" -o -s $OUTPUT ] ; then
printf "\nChecking root sh paths, umask values:\n$list\n"
if [ -s $OUTPUT ]; then
cat $OUTPUT
fi
if [ $umaskset = "no" ] ; then
printf "\tRoot sh startup files do not set the umask.\n"
fi
fi
fi
# Root and uucp should both be in /etc/ftpusers.
# XXX This should be updated to support the new format...
if [ "$check_ftpusers" = YES ]; then
list="root uucp"
for i in $list; do
if ! egrep "^$i$" /etc/ftpusers > /dev/null ; then
printf "\n$i is not listed in /etc/ftpusers file.\n"
fi
done
fi
# Uudecode should not be in the /etc/aliases file.
if [ "$check_aliases" = YES ]; then
if egrep '^[^#]*(uudecode|decode).*\|' /etc/aliases; then
printf "\nEntry for uudecode in /etc/aliases file.\n"
fi
fi
# Files that should not have + signs.
if [ "$check_rhosts" = YES ]; then
list="/etc/hosts.equiv /etc/hosts.lpd"
for f in $list ; do
if [ -f $f ] && egrep '\+' $f > /dev/null ; then
printf "\nPlus sign in $f file.\n"
fi
done
# Check for special users with .rhosts files. Only root and toor should
# have .rhosts files. Also, .rhosts files should not have plus signs.
awk -F: '$1 != "root" && $1 != "toor" && \
($3 < 100 || $1 == "ftp" || $1 == "uucp") \
{ print $1 " " $9 }' $MP |
sort -k2 |
while read uid homedir; do
if [ -f ${homedir}/.rhosts ] ; then
rhost=`ls -ldgT ${homedir}/.rhosts`
printf "$uid: $rhost\n"
fi
done > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking for special users with .rhosts files.\n"
cat $OUTPUT
fi
while read uid homedir; do
if [ -f ${homedir}/.rhosts ] && \
egrep '\+' ${homedir}/.rhosts > /dev/null ; then
printf "$uid: + in .rhosts file.\n"
fi
done < $MPPATH > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking .rhosts files syntax.\n"
cat $OUTPUT
fi
fi
# Check home directories. Directories should not be owned by someone else
# or writeable.
if [ "$check_homes" = YES ]; then
while read uid homedir; do
if [ -d ${homedir}/ ] ; then
file=`ls -ldgT ${homedir}`
printf "$uid $file\n"
fi
done < $MPPATH |
awk '$1 != $4 && $4 != "root" \
{ print "user " $1 " home directory is owned by " $4 }
$2 ~ /^-....w/ \
{ print "user " $1 " home directory is group writeable" }
$2 ~ /^-.......w/ \
{ print "user " $1 " home directory is other writeable" }' \
> $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking home directories.\n"
cat $OUTPUT
fi
# Files that should not be owned by someone else or readable.
list=".Xauthority .netrc"
while read uid homedir; do
for f in $list ; do
file=${homedir}/${f}
if [ -f $file ] ; then
printf "$uid $f `ls -ldgT $file`\n"
fi
done
done < $MPPATH |
awk '$1 != $5 && $5 != "root" \
{ print "user " $1 " " $2 " file is owned by " $5 }
$3 ~ /^-...r/ \
{ print "user " $1 " " $2 " file is group readable" }
$3 ~ /^-......r/ \
{ print "user " $1 " " $2 " file is other readable" }
$3 ~ /^-....w/ \
{ print "user " $1 " " $2 " file is group writeable" }
$3 ~ /^-.......w/ \
{ print "user " $1 " " $2 " file is other writeable" }' \
> $OUTPUT
# Files that should not be owned by someone else or writeable.
list=".bash_history .bash_login .bash_logout .bash_profile .bashrc \
.cshrc .emacs .exrc .forward .history .klogin .login .logout \
.profile .qmail .rc_history .rhosts .tcshrc .twmrc .xinitrc \
.xsession"
while read uid homedir; do
for f in $list ; do
file=${homedir}/${f}
if [ -f $file ] ; then
printf "$uid $f `ls -ldgT $file`\n"
fi
done
done < $MPPATH |
awk '$1 != $5 && $5 != "root" \
{ print "user " $1 " " $2 " file is owned by " $5 }
$3 ~ /^-....w/ \
{ print "user " $1 " " $2 " file is group writeable" }
$3 ~ /^-.......w/ \
{ print "user " $1 " " $2 " file is other writeable" }' \
>> $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking dot files.\n"
cat $OUTPUT
fi
fi
# Mailboxes should be owned by user and unreadable.
if [ "$check_varmail" = YES ]; then
ls -l /var/mail | sed 1d | \
awk '$3 != $9 \
{ print "user " $9 " mailbox is owned by " $3 }
$1 != "-rw-------" \
{ print "user " $9 " mailbox is " $1 ", group " $4 }' > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking mailbox ownership.\n"
cat $OUTPUT
fi
fi
if [ "$check_nfs" = YES ]; then
if [ -f /etc/exports ]; then
# File systems should not be globally exported.
awk '{
# ignore comments and blank lines
if ($LINE ~ /^\#/ || $LINE ~ /^$/ )
next;
readonly = 0;
for (i = 2; i <= NF; ++i) {
if ($i ~ /-ro/)
readonly = 1;
else if ($i !~ /^-/)
next;
}
if (readonly)
print "File system " $1 " globally exported, read-only."
else
print "File system " $1 " globally exported, read-write."
}' < /etc/exports > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking for globally exported file systems.\n"
cat $OUTPUT
fi
fi
fi
# Display any changes in setuid files and devices.
if [ "$check_devices" = YES ]; then
printf "\nChecking setuid files and devices:\n"
(find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \
-o -fstype procfs \) -a -prune -o \
\( \( -perm -u+s -a ! -type d \) -o \
\( -perm -g+s -a ! -type d \) -o \
-type b -o -type c \) -print0 | \
xargs -0 ls -ldgTq | sort +9 > $LIST) 2> $OUTPUT
# Display any errors that occurred during system file walk.
if [ -s $OUTPUT ] ; then
printf "Setuid/device find errors:\n"
cat $OUTPUT
printf "\n"
fi
# Display any changes in the setuid file list.
egrep -v '^[bc]' $LIST > $TMP1
if [ -s $TMP1 ] ; then
# Check to make sure uudecode isn't setuid.
if grep -w uudecode $TMP1 > /dev/null ; then
printf "\nUudecode is setuid.\n"
fi
CUR=/var/backups/setuid.current
BACK=/var/backups/setuid.backup
if [ -s $CUR ] ; then
if cmp -s $CUR $TMP1 ; then
:
else
> $TMP2
join -110 -210 -v2 $CUR $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Setuid additions:\n"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
join -110 -210 -v1 $CUR $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Setuid deletions:\n"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
sort -k10 $TMP2 $CUR $TMP1 | \
sed -e 's/[ ][ ]*/ /g' | \
uniq -u > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Setuid changes:\n"
column -t $OUTPUT
printf "\n"
fi
cp $CUR $BACK
cp $TMP1 $CUR
fi
else
printf "Setuid additions:\n"
column -t $TMP1
printf "\n"
cp $TMP1 $CUR
fi
fi
# Check for block and character disk devices that are readable or
# writeable or not owned by root.operator.
>$TMP1
DISKLIST="acd ccd cd ch fd hk hp mcd md ra rb rd rl rx rz \
sd se ss tz uk up vnd wd xd xy"
# DISKLIST="$DISKLIST ct mt st wt"
for i in $DISKLIST; do
egrep "^b.*/${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1
egrep "^c.*/r${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1
done
awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \
{ printf "Disk %s is user %s, group %s, permissions %s.\n", \
$11, $3, $4, $1; }' < $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking disk ownership and permissions.\n"
cat $OUTPUT
printf "\n"
fi
# Display any changes in the device file list.
egrep '^[bc]' $LIST | sort -k11 > $TMP1
if [ -s $TMP1 ] ; then
CUR=/var/backups/device.current
BACK=/var/backups/device.backup
if [ -s $CUR ] ; then
if cmp -s $CUR $TMP1 ; then
:
else
> $TMP2
join -111 -211 -v2 $CUR $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Device additions:\n"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
join -111 -211 -v1 $CUR $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Device deletions:\n"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
# Report any block device change. Ignore
# character devices, only the name is
# significant.
cat $TMP2 $CUR $TMP1 | \
sed -e '/^c/d' | \
sort -k11 | \
sed -e 's/[ ][ ]*/ /g' | \
uniq -u > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Block device changes:\n"
column -t $OUTPUT
printf "\n"
fi
cp $CUR $BACK
cp $TMP1 $CUR
fi
else
printf "Device additions:\n"
column -t $TMP1
printf "\n"
cp $TMP1 $CUR
fi
fi
fi
# Check special files.
# Check system binaries.
#
# Create the mtree tree specifications using:
#
# mtree -cx -pDIR -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure
# chown root.wheel DIR.secure
# chmod 600 DIR.secure
#
# Note, this is not complete protection against Trojan horsed binaries, as
# the hacker can modify the tree specification to match the replaced binary.
# For details on really protecting yourself against modified binaries, see
# the mtree(8) manual page.
if [ "$check_mtree" = YES ]; then
mtree -e -p / -f /etc/mtree/special > $OUTPUT
if [ -s $OUTPUT ]; then
printf "\nChecking special files and directories.\n"
cat $OUTPUT
fi
> $OUTPUT
for file in /etc/mtree/*.secure; do
[ $file = '/etc/mtree/*.secure' ] && continue
tree=`sed -n -e '3s/.* //p' -e 3q $file`
mtree -f $file -p $tree > $TMP1
if [ -s $TMP1 ]; then
printf "\nChecking $tree:\n" >> $OUTPUT
cat $TMP1 >> $OUTPUT
fi
done
if [ -s $OUTPUT ]; then
printf "\nChecking system binaries:\n"
cat $OUTPUT
fi
fi
# List of files that get backed up and checked for any modifications. Each
# file is expected to have two backups, /var/backups/file.{current,backup}.
# Any changes cause the files to rotate.
if [ "$check_changelist" = YES ] && [ -s /etc/changelist ] ; then
for file in `egrep -v "^#|$MP" /etc/changelist`; do
CUR=/var/backups/`basename $file`.current
BACK=/var/backups/`basename $file`.backup
if [ -s $file ]; then
if [ -s $CUR ] ; then
diff $CUR $file > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file
cat $OUTPUT
cp -p $CUR $BACK
cp -p $file $CUR
chown root.wheel $CUR $BACK
fi
else
cp -p $file $CUR
chown root.wheel $CUR
fi
fi
done
fi