security revision 1.32 1 #!/bin/sh -
2 #
3 # $NetBSD: security,v 1.32 1998/08/25 13:47:29 lukem Exp $
4 # from: @(#)security 8.1 (Berkeley) 6/9/93
5 #
6
7 PATH=/sbin:/usr/sbin:/bin:/usr/bin
8
9 if [ -f /etc/rc.subr ]; then
10 . /etc/rc.subr
11 else
12 echo "Can't read /etc/rc.subr; aborting."
13 exit 1;
14 fi
15
16 umask 077
17
18 if [ -s /etc/security.conf ]; then
19 . /etc/security.conf
20 fi
21
22 SECUREDIR=/tmp/_securedir.$$
23 if ! mkdir $SECUREDIR; then
24 echo can not create $SECUREDIR.
25 exit 1
26 fi
27
28 if ! cd $SECUREDIR; then
29 echo can not chdir to $SECUREDIR.
30 exit 1
31 fi
32
33 ERR=secure1.$$
34 TMP1=secure2.$$
35 TMP2=secure3.$$
36 MPBYUID=secure4.$$
37 MPBYPATH=secure5.$$
38 LIST=secure6.$$
39 OUTPUT=secure7.$$
40 LABELS=secure8.$$
41
42 trap '/bin/rm -rf $SECUREDIR ; exit 0' 0 2 3
43
44 MP=/etc/master.passwd
45
46 # these is used several times.
47 awk -F: '{ print $1 " " $3 }' $MP | sort -k2n > $MPBYUID
48 awk -F: '{ print $1 " " $9 }' $MP | sort -k2 > $MPBYPATH
49
50 # Check the master password file syntax.
51 #
52 if checkyesno check_passwd; then
53 awk '
54 BEGIN {
55 while ( getline < "/etc/shells" > 0 ) {
56 if ($LINE ~ /^\#/ || $LINE ~ /^$/ )
57 continue;
58 shells[$1]++;
59 }
60 FS=":";
61 }
62
63 {
64 if ($0 ~ /^[ ]*$/) {
65 printf "Line %d is a blank line.\n", NR;
66 next;
67 }
68 if (NF != 10)
69 printf "Line %d has the wrong number of fields.\n", NR;
70 if ($1 !~ /^[A-Za-z0-9]*$/)
71 printf "Login %s has non-alphanumeric characters.\n",
72 $1;
73 if (length($1) > 8)
74 printf "Login %s has more than 8 characters.\n", $1;
75 if ($2 == "")
76 printf "Login %s has no password.\n", $1;
77 if (length($2) != 13 && $2 != "") {
78 if ($10 == "" || shells[$10])
79 printf "Login %s is off but still has a valid shell (%s)\n",
80 $1, $10;
81 } else if (! shells[$10])
82 printf "Login %s does not have a valid shell (%s)\n",
83 $1, $10;
84 if ($3 == 0 && $1 != "root" && $1 != "toor")
85 printf "Login %s has a user id of 0.\n", $1;
86 if ($3 < 0)
87 printf "Login %s has a negative user id.\n", $1;
88 if ($4 < 0)
89 printf "Login %s has a negative group id.\n", $1;
90 }' < $MP > $OUTPUT
91 if [ -s $OUTPUT ] ; then
92 printf "\nChecking the $MP file:\n"
93 cat $OUTPUT
94 fi
95
96 awk -F: '{ print $1 }' $MP | sort | uniq -d > $OUTPUT
97 if [ -s $OUTPUT ] ; then
98 printf "\n$MP has duplicate user names.\n"
99 column $OUTPUT
100 fi
101
102 < $MPBYUID uniq -d -f 1 | awk '{ print $2 }' > $TMP2
103 if [ -s $TMP2 ] ; then
104 printf "\n$MP has duplicate user id's.\n"
105 while read uid; do
106 grep -w $uid $MPBYUID
107 done < $TMP2 | column
108 fi
109 fi
110
111 # Backup the master password file; a special case, the normal backup
112 # mechanisms also print out file differences and we don't want to do
113 # that because this file has encrypted passwords in it.
114 #
115 CUR=/var/backups/`basename $MP`.current
116 BACK=/var/backups/`basename $MP`.backup
117 if [ -s $CUR ] ; then
118 if cmp -s $CUR $MP; then
119 :
120 else
121 cp -p $CUR $BACK
122 cp -p $MP $CUR
123 chown root.wheel $CUR
124 fi
125 else
126 cp -p $MP $CUR
127 chown root.wheel $CUR
128 fi
129
130 # Check the group file syntax.
131 #
132 if checkyesno check_group; then
133 GRP=/etc/group
134 awk -F: '{
135 if ($0 ~ /^[ ]*$/) {
136 printf "Line %d is a blank line.\n", NR;
137 next;
138 }
139 if (NF != 4)
140 printf "Line %d has the wrong number of fields.\n", NR;
141 if ($1 !~ /^[A-za-z0-9]*$/)
142 printf "Group %s has non-alphanumeric characters.\n",
143 $1;
144 if (length($1) > 8)
145 printf "Group %s has more than 8 characters.\n", $1;
146 if ($3 !~ /[0-9]*/)
147 printf "Login %s has a negative group id.\n", $1;
148 }' < $GRP > $OUTPUT
149 if [ -s $OUTPUT ] ; then
150 printf "\nChecking the $GRP file:\n"
151 cat $OUTPUT
152 fi
153
154 awk -F: '{ print $1 }' $GRP | sort | uniq -d > $OUTPUT
155 if [ -s $OUTPUT ] ; then
156 printf "\n$GRP has duplicate group names.\n"
157 column $OUTPUT
158 fi
159 fi
160
161 # Check for root paths, umask values in startup files.
162 # The check for the root paths is problematical -- it's likely to fail
163 # in other environments. Once the shells have been modified to warn
164 # of '.' in the path, the path tests should go away.
165 #
166 if checkyesno check_rootdotfiles; then
167 > $OUTPUT
168 rhome=`csh -fc "echo ~root"`
169 umaskset=no
170 list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login"
171 for i in $list ; do
172 if [ -f $i ] ; then
173 if egrep umask $i > /dev/null ; then
174 umaskset=yes
175 fi
176 egrep umask $i |
177 awk '$2 % 100 < 20 \
178 { print "\tRoot umask is group writeable" }
179 $2 % 10 < 2 \
180 { print "\tRoot umask is other writeable" }' \
181 >> $OUTPUT
182 SAVE_PATH=$PATH
183 unset PATH
184 /bin/csh -f -s << end-of-csh > /dev/null 2>&1
185 source $i
186 /bin/ls -ldgT \$path > $TMP1
187 end-of-csh
188 PATH=$SAVE_PATH
189 awk '{
190 if ($10 ~ /^\.$/) {
191 print "\tThe root path includes .";
192 next;
193 }
194 }
195 $1 ~ /^d....w/ \
196 { print "\tRoot path directory " $10 " is group writeable." } \
197 $1 ~ /^d.......w/ \
198 { print "\tRoot path directory " $10 " is other writeable." }' \
199 < $TMP1 >> $OUTPUT
200 fi
201 done
202 if [ $umaskset = "no" -o -s $OUTPUT ] ; then
203 printf "\nChecking root csh paths, umask values:\n$list\n\n"
204 if [ -s $OUTPUT ]; then
205 cat $OUTPUT
206 fi
207 if [ $umaskset = "no" ] ; then
208 printf "\tRoot csh startup files do not set the umask.\n"
209 fi
210 fi
211
212 > $OUTPUT
213 rhome=/root
214 umaskset=no
215 list="/etc/profile ${rhome}/.profile"
216 for i in $list; do
217 if [ -f $i ] ; then
218 if egrep umask $i > /dev/null ; then
219 umaskset=yes
220 fi
221 egrep umask $i |
222 awk '$2 % 100 < 20 \
223 { print "\tRoot umask is group writeable" } \
224 $2 % 10 < 2 \
225 { print "\tRoot umask is other writeable" }' \
226 >> $OUTPUT
227 SAVE_PATH=$PATH
228 unset PATH
229 /bin/sh << end-of-sh > /dev/null 2>&1
230 . $i
231 list=\`echo \$PATH | /usr/bin/sed -e \
232 's/^:/.:/;s/:$/:./;s/::/:.:/g;s/:/ /g'\`
233 /bin/ls -ldgT \$list > $TMP1
234 end-of-sh
235 PATH=$SAVE_PATH
236 awk '{
237 if ($10 ~ /^\.$/) {
238 print "\tThe root path includes .";
239 next;
240 }
241 }
242 $1 ~ /^d....w/ \
243 { print "\tRoot path directory " $10 " is group writeable." } \
244 $1 ~ /^d.......w/ \
245 { print "\tRoot path directory " $10 " is other writeable." }' \
246 < $TMP1 >> $OUTPUT
247
248 fi
249 done
250 if [ $umaskset = "no" -o -s $OUTPUT ] ; then
251 printf "\nChecking root sh paths, umask values:\n$list\n"
252 if [ -s $OUTPUT ]; then
253 cat $OUTPUT
254 fi
255 if [ $umaskset = "no" ] ; then
256 printf "\tRoot sh startup files do not set the umask.\n"
257 fi
258 fi
259 fi
260
261 # Root and uucp should both be in /etc/ftpusers.
262 #
263 if checkyesno check_ftpusers; then
264 > $OUTPUT
265 list="uucp "`awk '$2 == 0 { print $1 }' $MPBYUID`
266 for i in $list; do
267 if /usr/libexec/ftpd -C $i ; then
268 printf "\t$i is not denied\n" >> $OUTPUT
269 fi
270 done
271 if [ -s $OUTPUT ]; then
272 printf "\nChecking the /etc/ftpusers configuration:\n"
273 cat $OUTPUT
274 fi
275 fi
276
277 # Uudecode should not be in the /etc/aliases file.
278 #
279 if checkyesno check_aliases; then
280 if egrep '^[^#]*(uudecode|decode).*\|' /etc/aliases; then
281 printf "\nEntry for uudecode in /etc/aliases file.\n"
282 fi
283 fi
284
285 # Files that should not have + signs.
286 #
287 if checkyesno check_rhosts; then
288 list="/etc/hosts.equiv /etc/hosts.lpd"
289 for f in $list ; do
290 if [ -f $f ] && egrep '\+' $f > /dev/null ; then
291 printf "\nPlus sign in $f file.\n"
292 fi
293 done
294
295 # Check for special users with .rhosts files. Only root and toor should
296 # have .rhosts files. Also, .rhosts files should not have plus signs.
297 awk -F: '$1 != "root" && $1 != "toor" && \
298 ($3 < 100 || $1 == "ftp" || $1 == "uucp") \
299 { print $1 " " $9 }' $MP |
300 sort -k2 |
301 while read uid homedir; do
302 if [ -f ${homedir}/.rhosts ] ; then
303 rhost=`ls -ldgT ${homedir}/.rhosts`
304 printf "$uid: $rhost\n"
305 fi
306 done > $OUTPUT
307 if [ -s $OUTPUT ] ; then
308 printf "\nChecking for special users with .rhosts files.\n"
309 cat $OUTPUT
310 fi
311
312 while read uid homedir; do
313 if [ -f ${homedir}/.rhosts ] && \
314 egrep '\+' ${homedir}/.rhosts > /dev/null ; then
315 printf "$uid: + in .rhosts file.\n"
316 fi
317 done < $MPBYPATH > $OUTPUT
318 if [ -s $OUTPUT ] ; then
319 printf "\nChecking .rhosts files syntax.\n"
320 cat $OUTPUT
321 fi
322 fi
323
324 # Check home directories. Directories should not be owned by someone else
325 # or writeable.
326 #
327 if checkyesno check_homes; then
328 while read uid homedir; do
329 if [ -d ${homedir}/ ] ; then
330 file=`ls -ldgT ${homedir}`
331 printf "$uid $file\n"
332 fi
333 done < $MPBYPATH |
334 awk '$1 != $4 && $4 != "root" \
335 { print "user " $1 " home directory is owned by " $4 }
336 $2 ~ /^-....w/ \
337 { print "user " $1 " home directory is group writeable" }
338 $2 ~ /^-.......w/ \
339 { print "user " $1 " home directory is other writeable" }' \
340 > $OUTPUT
341 if [ -s $OUTPUT ] ; then
342 printf "\nChecking home directories.\n"
343 cat $OUTPUT
344 fi
345
346 # Files that should not be owned by someone else or readable.
347 list=".Xauthority .netrc"
348 while read uid homedir; do
349 for f in $list ; do
350 file=${homedir}/${f}
351 if [ -f $file ] ; then
352 printf "$uid $f `ls -ldgT $file`\n"
353 fi
354 done
355 done < $MPBYPATH |
356 awk '$1 != $5 && $5 != "root" \
357 { print "user " $1 " " $2 " file is owned by " $5 }
358 $3 ~ /^-...r/ \
359 { print "user " $1 " " $2 " file is group readable" }
360 $3 ~ /^-......r/ \
361 { print "user " $1 " " $2 " file is other readable" }
362 $3 ~ /^-....w/ \
363 { print "user " $1 " " $2 " file is group writeable" }
364 $3 ~ /^-.......w/ \
365 { print "user " $1 " " $2 " file is other writeable" }' \
366 > $OUTPUT
367
368 # Files that should not be owned by someone else or writeable.
369 list=".bash_history .bash_login .bash_logout .bash_profile .bashrc \
370 .cshrc .emacs .exrc .forward .history .klogin .login .logout \
371 .profile .qmail .rc_history .rhosts .tcshrc .twmrc .xinitrc \
372 .xsession"
373 while read uid homedir; do
374 for f in $list ; do
375 file=${homedir}/${f}
376 if [ -f $file ] ; then
377 printf "$uid $f `ls -ldgT $file`\n"
378 fi
379 done
380 done < $MPBYPATH |
381 awk '$1 != $5 && $5 != "root" \
382 { print "user " $1 " " $2 " file is owned by " $5 }
383 $3 ~ /^-....w/ \
384 { print "user " $1 " " $2 " file is group writeable" }
385 $3 ~ /^-.......w/ \
386 { print "user " $1 " " $2 " file is other writeable" }' \
387 >> $OUTPUT
388 if [ -s $OUTPUT ] ; then
389 printf "\nChecking dot files.\n"
390 cat $OUTPUT
391 fi
392 fi
393
394 # Mailboxes should be owned by user and unreadable.
395 #
396 if checkyesno check_varmail; then
397 ls -l /var/mail | sed 1d | \
398 awk '$3 != $9 \
399 { print "user " $9 " mailbox is owned by " $3 }
400 $1 != "-rw-------" \
401 { print "user " $9 " mailbox is " $1 ", group " $4 }' > $OUTPUT
402 if [ -s $OUTPUT ] ; then
403 printf "\nChecking mailbox ownership.\n"
404 cat $OUTPUT
405 fi
406 fi
407
408 # NFS exports shouldn't be globally exported
409 #
410 if checkyesno check_nfs && [ -f /etc/exports ]; then
411 awk '{
412 # ignore comments and blank lines
413 if ($LINE ~ /^\#/ || $LINE ~ /^$/ )
414 next;
415
416 readonly = 0;
417 for (i = 2; i <= NF; ++i) {
418 if ($i ~ /-ro/)
419 readonly = 1;
420 else if ($i !~ /^-/)
421 next;
422 }
423 if (readonly)
424 print "File system " $1 " globally exported, read-only."
425 else
426 print "File system " $1 " globally exported, read-write."
427 }' < /etc/exports > $OUTPUT
428 if [ -s $OUTPUT ] ; then
429 printf "\nChecking for globally exported file systems.\n"
430 cat $OUTPUT
431 fi
432 fi
433
434 # Display any changes in setuid files and devices.
435 #
436 if checkyesno check_devices; then
437 > $ERR
438 (find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \
439 -o -fstype procfs \) -a -prune -o \
440 \( \( -perm -u+s -a ! -type d \) -o \
441 \( -perm -g+s -a ! -type d \) -o \
442 -type b -o -type c \) -print0 | \
443 xargs -0 ls -ldgTq | sort +9 > $LIST) 2> $OUTPUT
444
445 # Display any errors that occurred during system file walk.
446 if [ -s $OUTPUT ] ; then
447 printf "Setuid/device find errors:\n" >> $ERR
448 cat $OUTPUT >> $ERR
449 printf "\n" >> $ERR
450 fi
451
452 # Display any changes in the setuid file list.
453 egrep -v '^[bc]' $LIST > $TMP1
454 if [ -s $TMP1 ] ; then
455 # Check to make sure uudecode isn't setuid.
456 if grep -w uudecode $TMP1 > /dev/null ; then
457 printf "\nUudecode is setuid.\n" >> $ERR
458 fi
459
460 CUR=/var/backups/setuid.current
461 BACK=/var/backups/setuid.backup
462
463 if [ -s $CUR ] ; then
464 if cmp -s $CUR $TMP1 ; then
465 :
466 else
467 > $TMP2
468 join -110 -210 -v2 $CUR $TMP1 > $OUTPUT
469 if [ -s $OUTPUT ] ; then
470 printf "Setuid additions:\n" >> $ERR
471 tee -a $TMP2 < $OUTPUT >> $ERR
472 printf "\n" >> $ERR
473 fi
474
475 join -110 -210 -v1 $CUR $TMP1 > $OUTPUT
476 if [ -s $OUTPUT ] ; then
477 printf "Setuid deletions:\n" >> $ERR
478 tee -a $TMP2 < $OUTPUT >> $ERR
479 printf "\n" >> $ERR
480 fi
481
482 sort -k10 $TMP2 $CUR $TMP1 | \
483 sed -e 's/[ ][ ]*/ /g' | \
484 uniq -u > $OUTPUT
485 if [ -s $OUTPUT ] ; then
486 printf "Setuid changes:\n" >> $ERR
487 column -t $OUTPUT >> $ERR
488 printf "\n" >> $ERR
489 fi
490
491 cp $CUR $BACK
492 cp $TMP1 $CUR
493 fi
494 else
495 printf "Setuid additions:\n" >> $ERR
496 column -t $TMP1 >> $ERR
497 printf "\n" >> $ERR
498 cp $TMP1 $CUR
499 fi
500 fi
501
502 # Check for block and character disk devices that are readable or
503 # writeable or not owned by root.operator.
504 >$TMP1
505 DISKLIST="acd ccd cd ch fd hk hp mcd md ra rb rd rl rx rz \
506 sd se ss tz uk up vnd wd xd xy"
507 # DISKLIST="$DISKLIST ct mt st wt"
508 for i in $DISKLIST; do
509 egrep "^b.*/${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1
510 egrep "^c.*/r${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1
511 done
512
513 awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \
514 { printf "Disk %s is user %s, group %s, permissions %s.\n", \
515 $11, $3, $4, $1; }' < $TMP1 > $OUTPUT
516 if [ -s $OUTPUT ] ; then
517 printf "\nChecking disk ownership and permissions.\n" >> $ERR
518 cat $OUTPUT >> $ERR
519 printf "\n" >> $ERR
520 fi
521
522 # Display any changes in the device file list.
523 egrep '^[bc]' $LIST | sort -k11 > $TMP1
524 if [ -s $TMP1 ] ; then
525 CUR=/var/backups/device.current
526 BACK=/var/backups/device.backup
527
528 if [ -s $CUR ] ; then
529 if cmp -s $CUR $TMP1 ; then
530 :
531 else
532 > $TMP2
533 join -111 -211 -v2 $CUR $TMP1 > $OUTPUT
534 if [ -s $OUTPUT ] ; then
535 printf "Device additions:\n" >> $ERR
536 tee -a $TMP2 < $OUTPUT >> $ERR
537 printf "\n" >> $ERR
538 fi
539
540 join -111 -211 -v1 $CUR $TMP1 > $OUTPUT
541 if [ -s $OUTPUT ] ; then
542 printf "Device deletions:\n" >> $ERR
543 tee -a $TMP2 < $OUTPUT >> $ERR
544 printf "\n" >> $ERR
545 fi
546
547 # Report any block device change. Ignore
548 # character devices, only the name is
549 # significant.
550 cat $TMP2 $CUR $TMP1 | \
551 sed -e '/^c/d' | \
552 sort -k11 | \
553 sed -e 's/[ ][ ]*/ /g' | \
554 uniq -u > $OUTPUT
555 if [ -s $OUTPUT ] ; then
556 printf "Block device changes:\n" >> $ERR
557 column -t $OUTPUT >> $ERR
558 printf "\n" >> $ERR
559 fi
560
561 cp $CUR $BACK
562 cp $TMP1 $CUR
563 fi
564 else
565 printf "Device additions:\n" >> $ERR
566 column -t $TMP1 >> $ERR
567 printf "\n" >> $ERR
568 cp $TMP1 $CUR >> $ERR
569 fi
570 fi
571 if [ -s $ERR ] ; then
572 printf "\nChecking setuid files and devices:\n"
573 cat $ERR
574 printf "\n"
575 fi
576 fi
577
578 # Check special files.
579 # Check system binaries.
580 #
581 # Create the mtree tree specifications using:
582 #
583 # mtree -cx -pDIR -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure
584 # chown root.wheel DIR.secure
585 # chmod 600 DIR.secure
586 #
587 # Note, this is not complete protection against Trojan horsed binaries, as
588 # the hacker can modify the tree specification to match the replaced binary.
589 # For details on really protecting yourself against modified binaries, see
590 # the mtree(8) manual page.
591 #
592 if checkyesno check_mtree; then
593 mtree -e -p / -f /etc/mtree/special > $OUTPUT
594 if [ -s $OUTPUT ]; then
595 printf "\nChecking special files and directories.\n"
596 cat $OUTPUT
597 fi
598
599 > $OUTPUT
600 for file in /etc/mtree/*.secure; do
601 [ $file = '/etc/mtree/*.secure' ] && continue
602 tree=`sed -n -e '3s/.* //p' -e 3q $file`
603 mtree -f $file -p $tree > $TMP1
604 if [ -s $TMP1 ]; then
605 printf "\nChecking $tree:\n" >> $OUTPUT
606 cat $TMP1 >> $OUTPUT
607 fi
608 done
609 if [ -s $OUTPUT ]; then
610 printf "\nChecking system binaries:\n"
611 cat $OUTPUT
612 fi
613 fi
614
615 CHANGELIST=""
616
617 # Backup disklabels of available disks
618 #
619 if checkyesno check_disklabels; then
620 # generate list of old disklabels and remove them
621 ls -1d /var/backups/disklabel.* 2>/dev/null |
622 egrep -v '\.(backup|current)$' > $LABELS
623 xargs rm < $LABELS
624
625 disks=`iostat -x | sed 1d | awk '$1 !~ /^[mf]d/ { print $1; }'`
626 for i in $disks; do
627 dlf="/var/backups/disklabel.$i"
628 disklabel $i > $dlf 2>/dev/null
629 done
630
631 # append list of new disklabels, sort list
632 ls -1d /var/backups/disklabel.* 2>/dev/null |
633 egrep -v '\.(backup|current)$' >> $LABELS
634 sort -u -o $LABELS $LABELS
635 CHANGELIST=$LABELS
636 fi
637
638 # List of files that get backed up and checked for any modifications. Each
639 # file is expected to have two backups, /var/backups/file.{current,backup}.
640 # Any changes cause the files to rotate.
641 #
642 if checkyesno check_changelist && [ -s /etc/changelist ] ; then
643 CHANGELIST="/etc/changelist $CHANGELIST"
644 fi
645
646 if [ -n "$CHANGELIST" ]; then
647 for file in `egrep -hv "^#|$MP" $CHANGELIST`; do
648 CUR=/var/backups/`basename $file`.current
649 BACK=/var/backups/`basename $file`.backup
650 if [ -f $file ]; then
651 if [ -f $CUR ] ; then
652 diff $CUR $file > $OUTPUT
653 if [ -s $OUTPUT ] ; then
654 printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file
655 cat $OUTPUT
656 mv -f $CUR $BACK
657 cp -p $file $CUR
658 chown root.wheel $CUR
659 fi
660 else
661 printf "\n======\n%s added\n======\n" $file
662 diff /dev/null $file
663 cp -p $file $CUR
664 chown root.wheel $CUR
665 fi
666 else
667 if [ -f $CUR ]; then
668 printf "\n======\n%s removed\n======\n" $file
669 diff $CUR /dev/null
670 mv -f $CUR $BACK
671 fi
672 fi
673 done
674 fi
675