Annotation of src/etc/security, Revision 1.2
1.1 deraadt 1: #!/bin/sh -
2: #
3: # from: @(#)security 8.1 (Berkeley) 6/9/93
1.2 ! deraadt 4: # $Id: security,v 1.1.1.1 1995/10/18 08:37:57 deraadt Exp $
1.1 deraadt 5: #
6:
7: PATH=/sbin:/usr/sbin:/bin:/usr/bin
8:
9: umask 077
10:
11: ERR=/tmp/_secure1.$$
12: TMP1=/tmp/_secure2.$$
13: TMP2=/tmp/_secure3.$$
14: TMP3=/tmp/_secure4.$$
15: LIST=/tmp/_secure5.$$
16: OUTPUT=/tmp/_secure6.$$
17:
18: trap 'rm -f $ERR $TMP1 $TMP2 $TMP3 $LIST $OUTPUT' 0
19:
20: # Check the master password file syntax.
21: MP=/etc/master.passwd
22: awk -F: '{
23: if ($0 ~ /^[ ]*$/) {
24: printf("Line %d is a blank line.\n", NR);
25: next;
26: }
27: if (NF != 10)
28: printf("Line %d has the wrong number of fields.\n", NR);
1.2 ! deraadt 29: if ($1 ~ /^[+-].*$/)
! 30: next;
! 31: if ($1 == "")
! 32: printf("Line %d has an empty login field.\n",NR);
! 33: else if ($1 !~ /^[A-Za-z0-9][A-Za-z0-9_-]*$/)
1.1 deraadt 34: printf("Login %s has non-alphanumeric characters.\n", $1);
35: if (length($1) > 8)
36: printf("Login %s has more than 8 characters.\n", $1);
37: if ($2 == "")
38: printf("Login %s has no password.\n", $1);
39: if (length($2) != 13 && ($10 ~ /.*sh$/ || $10 == ""))
40: printf("Login %s is off but still has a valid shell.\n", $1);
41: if ($3 == 0 && $1 != "root" && $1 != "toor")
42: printf("Login %s has a user id of 0.\n", $1);
43: if ($3 < 0)
44: printf("Login %s has a negative user id.\n", $1);
45: if ($4 < 0)
46: printf("Login %s has a negative group id.\n", $1);
47: }' < $MP > $OUTPUT
48: if [ -s $OUTPUT ] ; then
49: printf "\nChecking the $MP file:\n"
50: cat $OUTPUT
51: fi
52:
53: awk -F: '{ print $1 }' $MP | sort | uniq -d > $OUTPUT
54: if [ -s $OUTPUT ] ; then
55: printf "\n$MP has duplicate user names.\n"
56: column $OUTPUT
57: fi
58:
1.2 ! deraadt 59: awk -F: '$1 != "toor" { print $1 " " $3 }' $MP | sort -n +1 | tee $TMP1 |
1.1 deraadt 60: uniq -d -f 1 | awk '{ print $2 }' > $TMP2
61: if [ -s $TMP2 ] ; then
62: printf "\n$MP has duplicate user id's.\n"
63: while read uid; do
64: grep -w $uid $TMP1
65: done < $TMP2 | column
66: fi
67:
68: # Backup the master password file; a special case, the normal backup
69: # mechanisms also print out file differences and we don't want to do
70: # that because this file has encrypted passwords in it.
1.2 ! deraadt 71: if [ ! -d /var/backups ] ; then
! 72: mkdir /var/backups
! 73: chmod 755 /var/backups
! 74: fi
1.1 deraadt 75: CUR=/var/backups/`basename $MP`.current
76: BACK=/var/backups/`basename $MP`.backup
77: if [ -s $CUR ] ; then
78: if cmp -s $CUR $MP; then
79: :
80: else
81: cp -p $CUR $BACK
82: cp -p $MP $CUR
83: chown root.wheel $CUR
84: fi
85: else
86: cp -p $MP $CUR
87: chown root.wheel $CUR
88: fi
89:
90: # Check the group file syntax.
91: GRP=/etc/group
92: awk -F: '{
93: if ($0 ~ /^[ ]*$/) {
94: printf("Line %d is a blank line.\n", NR);
95: next;
96: }
1.2 ! deraadt 97: if ($1 ~ /^[+-].*$/)
! 98: next;
1.1 deraadt 99: if (NF != 4)
100: printf("Line %d has the wrong number of fields.\n", NR);
101: if ($1 !~ /^[A-za-z0-9]*$/)
102: printf("Group %s has non-alphanumeric characters.\n", $1);
103: if (length($1) > 8)
104: printf("Group %s has more than 8 characters.\n", $1);
105: if ($3 !~ /[0-9]*/)
106: printf("Login %s has a negative group id.\n", $1);
107: }' < $GRP > $OUTPUT
108: if [ -s $OUTPUT ] ; then
109: printf "\nChecking the $GRP file:\n"
110: cat $OUTPUT
111: fi
112:
113: awk -F: '{ print $1 }' $GRP | sort | uniq -d > $OUTPUT
114: if [ -s $OUTPUT ] ; then
115: printf "\n$GRP has duplicate group names.\n"
116: column $OUTPUT
117: fi
118:
119: # Check for root paths, umask values in startup files.
120: # The check for the root paths is problematical -- it's likely to fail
121: # in other environments. Once the shells have been modified to warn
122: # of '.' in the path, the path tests should go away.
123: > $OUTPUT
124: rhome=/root
125: umaskset=no
126: list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login"
127: for i in $list ; do
128: if [ -f $i ] ; then
129: if egrep umask $i > /dev/null ; then
130: umaskset=yes
131: fi
132: egrep umask $i |
133: awk '$2 % 100 < 20 \
134: { print "Root umask is group writeable" }
135: $2 % 10 < 2 \
136: { print "Root umask is other writeable" }' >> $OUTPUT
137: /bin/csh -f -s << end-of-csh > /dev/null 2>&1
138: unset path
139: source $i
140: /bin/ls -ldgT \$path > $TMP1
141: end-of-csh
142: awk '{
143: if ($10 ~ /^\.$/) {
144: print "The root path includes .";
145: next;
146: }
147: }
148: $1 ~ /^d....w/ \
149: { print "Root path directory " $10 " is group writeable." } \
150: $1 ~ /^d.......w/ \
151: { print "Root path directory " $10 " is other writeable." }' \
152: < $TMP1 >> $OUTPUT
153: fi
154: done
155: if [ $umaskset = "no" -o -s $OUTPUT ] ; then
156: printf "\nChecking root csh paths, umask values:\n$list\n"
157: if [ -s $OUTPUT ]; then
158: cat $OUTPUT
159: fi
160: if [ $umaskset = "no" ] ; then
161: printf "\nRoot csh startup files do not set the umask.\n"
162: fi
163: fi
164:
165: > $OUTPUT
166: rhome=/root
167: umaskset=no
168: list="${rhome}/.profile"
169: for i in $list; do
170: if [ -f $i ] ; then
171: if egrep umask $i > /dev/null ; then
172: umaskset=yes
173: fi
174: egrep umask $i |
175: awk '$2 % 100 < 20 \
176: { print "Root umask is group writeable" } \
177: $2 % 10 < 2 \
178: { print "Root umask is other writeable" }' >> $OUTPUT
179: /bin/sh << end-of-sh > /dev/null 2>&1
180: PATH=
181: . $i
182: list=\`echo \$PATH | /usr/bin/sed -e 's/:/ /g'\`
183: /bin/ls -ldgT \$list > $TMP1
184: end-of-sh
185: awk '{
186: if ($10 ~ /^\.$/) {
187: print "The root path includes .";
188: next;
189: }
190: }
191: $1 ~ /^d....w/ \
192: { print "Root path directory " $10 " is group writeable." } \
193: $1 ~ /^d.......w/ \
194: { print "Root path directory " $10 " is other writeable." }' \
195: < $TMP1 >> $OUTPUT
196:
197: fi
198: done
199: if [ $umaskset = "no" -o -s $OUTPUT ] ; then
200: printf "\nChecking root sh paths, umask values:\n$list\n"
201: if [ -s $OUTPUT ]; then
202: cat $OUTPUT
203: fi
204: if [ $umaskset = "no" ] ; then
205: printf "\nRoot sh startup files do not set the umask.\n"
206: fi
207: fi
208:
209: # Root and uucp should both be in /etc/ftpusers.
210: if egrep root /etc/ftpusers > /dev/null ; then
211: :
212: else
213: printf "\nRoot not listed in /etc/ftpusers file.\n"
214: fi
215: if egrep uucp /etc/ftpusers > /dev/null ; then
216: :
217: else
218: printf "\nUucp not listed in /etc/ftpusers file.\n"
219: fi
220:
221: # Uudecode should not be in the /etc/aliases file.
222: if egrep 'uudecode|decode' /etc/aliases; then
223: printf "\nThere is an entry for uudecode in the /etc/aliases file.\n"
224: fi
225:
226: # Files that should not have + signs.
1.2 ! deraadt 227: list="/etc/hosts.equiv /etc/shosts.equiv /etc/hosts.lpd"
1.1 deraadt 228: for f in $list ; do
1.2 ! deraadt 229: if [ -f $f ] ; then
! 230: awk '{
! 231: if ($0 ~ /^+@.*$/ )
! 232: next;
! 233: if ($0 ~ /^+.*$/ )
! 234: printf("\nPlus sign in %s file.\n", FILENAME);
! 235: }' $f
1.1 deraadt 236: fi
237: done
238:
1.2 ! deraadt 239: # Check for special users with .rhosts/.shosts files. Only root and
! 240: # toor should have .rhosts/.shosts files. Also, .rhosts/.shosts files
! 241: # should not have plus signs.
! 242: awk -F: '$1 != "root" && $1 != "toor" && $1 !~ /^[+-].*$/ && \
1.1 deraadt 243: ($3 < 100 || $1 == "ftp" || $1 == "uucp") \
244: { print $1 " " $6 }' /etc/passwd |
245: while read uid homedir; do
1.2 ! deraadt 246: for j in .rhosts .shosts; do
! 247: if [ -f ${homedir}/$j ] ; then
! 248: rhost=`ls -ldgT ${homedir}/$j`
! 249: printf "$uid: $rhost\n"
! 250: fi
! 251: done
1.1 deraadt 252: done > $OUTPUT
253: if [ -s $OUTPUT ] ; then
1.2 ! deraadt 254: printf "\nChecking for special users with .rhosts/.shosts files.\n"
1.1 deraadt 255: cat $OUTPUT
256: fi
257:
258: awk -F: '{ print $1 " " $6 }' /etc/passwd | \
259: while read uid homedir; do
1.2 ! deraadt 260: for j in .rhosts .shosts; do
! 261: if [ -f ${homedir}/$j ] ; then
! 262: awk '{
! 263: if ($0 ~ /^+@.*$/ )
! 264: next;
! 265: if ($0 ~ /^+.*$/ )
! 266: printf("%s has + sign in it.\n",
! 267: FILENAME);
! 268: }' ${homedir}/$j
! 269: fi
! 270: done
1.1 deraadt 271: done > $OUTPUT
272: if [ -s $OUTPUT ] ; then
1.2 ! deraadt 273: printf "\nChecking .rhosts/.shosts files syntax.\n"
1.1 deraadt 274: cat $OUTPUT
275: fi
276:
277: # Check home directories. Directories should not be owned by someone else
278: # or writeable.
1.2 ! deraadt 279: awk -F: '{ if ( $1 !~ /^[+-].*$/ ) print $1 " " $6 }' /etc/passwd | \
1.1 deraadt 280: while read uid homedir; do
281: if [ -d ${homedir}/ ] ; then
282: file=`ls -ldgT ${homedir}`
283: printf "$uid $file\n"
284: fi
285: done |
286: awk '$1 != $4 && $4 != "root" \
287: { print "user " $1 " home directory is owned by " $4 }
288: $2 ~ /^-....w/ \
289: { print "user " $1 " home directory is group writeable" }
290: $2 ~ /^-.......w/ \
291: { print "user " $1 " home directory is other writeable" }' > $OUTPUT
292: if [ -s $OUTPUT ] ; then
293: printf "\nChecking home directories.\n"
294: cat $OUTPUT
295: fi
296:
297: # Files that should not be owned by someone else or readable.
1.2 ! deraadt 298: list=".netrc .rhosts .shosts"
1.1 deraadt 299: awk -F: '{ print $1 " " $6 }' /etc/passwd | \
300: while read uid homedir; do
301: for f in $list ; do
302: file=${homedir}/${f}
303: if [ -f $file ] ; then
304: printf "$uid $f `ls -ldgT $file`\n"
305: fi
306: done
307: done |
308: awk '$1 != $5 && $5 != "root" \
309: { print "user " $1 " " $2 " file is owned by " $5 }
310: $3 ~ /^-......r/ \
311: { print "user " $1 " " $2 " file is other readable" }
312: $3 ~ /^-....w/ \
313: { print "user " $1 " " $2 " file is group writeable" }
314: $3 ~ /^-.......w/ \
315: { print "user " $1 " " $2 " file is other writeable" }' > $OUTPUT
316:
317: # Files that should not be owned by someone else or writeable.
318: list=".bashrc .cshrc .emacs .exrc .forward .klogin .login .logout \
319: .profile .tcshrc"
320: awk -F: '{ print $1 " " $6 }' /etc/passwd | \
321: while read uid homedir; do
322: for f in $list ; do
323: file=${homedir}/${f}
324: if [ -f $file ] ; then
325: printf "$uid $f `ls -ldgT $file`\n"
326: fi
327: done
328: done |
329: awk '$1 != $5 && $5 != "root" \
330: { print "user " $1 " " $2 " file is owned by " $5 }
331: $3 ~ /^-....w/ \
332: { print "user " $1 " " $2 " file is group writeable" }
333: $3 ~ /^-.......w/ \
334: { print "user " $1 " " $2 " file is other writeable" }' >> $OUTPUT
335: if [ -s $OUTPUT ] ; then
336: printf "\nChecking dot files.\n"
337: cat $OUTPUT
338: fi
339:
340: # Mailboxes should be owned by user and unreadable.
341: ls -l /var/mail | sed 1d | \
342: awk '$3 != $9 \
343: { print "user " $9 " mailbox is owned by " $3 }
344: $1 != "-rw-------" \
345: { print "user " $9 " mailbox is " $1 ", group " $4 }' > $OUTPUT
346: if [ -s $OUTPUT ] ; then
347: printf "\nChecking mailbox ownership.\n"
348: cat $OUTPUT
349: fi
350:
1.2 ! deraadt 351: if [ -f /etc/exports ]; then
! 352: # File systems should not be globally exported.
! 353: awk '{
1.1 deraadt 354: readonly = 0;
355: for (i = 2; i <= NF; ++i) {
356: if ($i ~ /-ro/)
357: readonly = 1;
358: else if ($i !~ /^-/)
359: next;
360: }
361: if (readonly)
362: print "File system " $1 " globally exported, read-only."
363: else
364: print "File system " $1 " globally exported, read-write."
1.2 ! deraadt 365: }' < /etc/exports > $OUTPUT
! 366: if [ -s $OUTPUT ] ; then
1.1 deraadt 367: printf "\nChecking for globally exported file systems.\n"
368: cat $OUTPUT
1.2 ! deraadt 369: fi
1.1 deraadt 370: fi
371:
372: # Display any changes in setuid files and devices.
1.2 ! deraadt 373: pending="\nChecking setuid files and devices:\n"
1.1 deraadt 374: (find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \
375: -o -fstype procfs \) -a -prune -o \
1.2 ! deraadt 376: -type f -a \( -perm -u+s -o -perm -g+s \) -print -o \
! 377: ! -type d -a ! -type f -a ! -type l -a ! -type s -print | \
1.1 deraadt 378: sort | sed -e 's/^/ls -ldgT /' | sh > $LIST) 2> $OUTPUT
379:
380: # Display any errors that occurred during system file walk.
381: if [ -s $OUTPUT ] ; then
1.2 ! deraadt 382: printf "${pending}Setuid/device find errors:\n"
! 383: pending=
1.1 deraadt 384: cat $OUTPUT
385: printf "\n"
386: fi
387:
388: # Display any changes in the setuid file list.
389: egrep -v '^[bc]' $LIST > $TMP1
390: if [ -s $TMP1 ] ; then
391: # Check to make sure uudecode isn't setuid.
392: if grep -w uudecode $TMP1 > /dev/null ; then
1.2 ! deraadt 393: printf "${pending}\nUudecode is setuid.\n"
! 394: pending=
1.1 deraadt 395: fi
396:
397: CUR=/var/backups/setuid.current
398: BACK=/var/backups/setuid.backup
399:
400: if [ -s $CUR ] ; then
401: if cmp -s $CUR $TMP1 ; then
402: :
403: else
404: > $TMP2
405: join -110 -210 -v2 $CUR $TMP1 > $OUTPUT
406: if [ -s $OUTPUT ] ; then
1.2 ! deraadt 407: printf "${pending}Setuid additions:\n"
! 408: pending=
1.1 deraadt 409: tee -a $TMP2 < $OUTPUT
410: printf "\n"
411: fi
412:
413: join -110 -210 -v1 $CUR $TMP1 > $OUTPUT
414: if [ -s $OUTPUT ] ; then
1.2 ! deraadt 415: printf "${pending}Setuid deletions:\n"
! 416: pending=
1.1 deraadt 417: tee -a $TMP2 < $OUTPUT
418: printf "\n"
419: fi
420:
421: sort +9 $TMP2 $CUR $TMP1 | \
422: sed -e 's/[ ][ ]*/ /g' | uniq -u > $OUTPUT
423: if [ -s $OUTPUT ] ; then
1.2 ! deraadt 424: printf "${pending}Setuid changes:\n"
! 425: pending=
1.1 deraadt 426: column -t $OUTPUT
427: printf "\n"
428: fi
429:
430: cp $CUR $BACK
431: cp $TMP1 $CUR
432: fi
433: else
1.2 ! deraadt 434: printf "${pending}Setuid additions:\n"
! 435: pending=
1.1 deraadt 436: column -t $TMP1
437: printf "\n"
438: cp $TMP1 $CUR
439: fi
440: fi
441:
442: # Check for block and character disk devices that are readable or writeable
443: # or not owned by root.operator.
444: >$TMP1
1.2 ! deraadt 445: DISKLIST="dk fd hd hk hp jb kra ra rb rd rl rx xd rz sd up wd vnd ccd"
1.1 deraadt 446: for i in $DISKLIST; do
447: egrep "^b.*/${i}[0-9][0-9]*[a-h]$" $LIST >> $TMP1
448: egrep "^c.*/r${i}[0-9][0-9]*[a-h]$" $LIST >> $TMP1
449: done
450:
451: awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \
452: { printf("Disk %s is user %s, group %s, permissions %s.\n", \
453: $11, $3, $4, $1); }' < $TMP1 > $OUTPUT
454: if [ -s $OUTPUT ] ; then
455: printf "\nChecking disk ownership and permissions.\n"
456: cat $OUTPUT
457: printf "\n"
458: fi
459:
460: # Display any changes in the device file list.
461: egrep '^[bc]' $LIST | sort +10 > $TMP1
462: if [ -s $TMP1 ] ; then
463: CUR=/var/backups/device.current
464: BACK=/var/backups/device.backup
465:
466: if [ -s $CUR ] ; then
467: if cmp -s $CUR $TMP1 ; then
468: :
469: else
470: > $TMP2
471: join -111 -211 -v2 $CUR $TMP1 > $OUTPUT
472: if [ -s $OUTPUT ] ; then
473: printf "Device additions:\n"
474: tee -a $TMP2 < $OUTPUT
475: printf "\n"
476: fi
477:
478: join -111 -211 -v1 $CUR $TMP1 > $OUTPUT
479: if [ -s $OUTPUT ] ; then
480: printf "Device deletions:\n"
481: tee -a $TMP2 < $OUTPUT
482: printf "\n"
483: fi
484:
485: # Report any block device change. Ignore character
486: # devices, only the name is significant.
487: cat $TMP2 $CUR $TMP1 | \
488: sed -e '/^c/d' | \
489: sort +10 | \
490: sed -e 's/[ ][ ]*/ /g' | \
491: uniq -u > $OUTPUT
492: if [ -s $OUTPUT ] ; then
493: printf "Block device changes:\n"
494: column -t $OUTPUT
495: printf "\n"
496: fi
497:
498: cp $CUR $BACK
499: cp $TMP1 $CUR
500: fi
501: else
502: printf "Device additions:\n"
503: column -t $TMP1
504: printf "\n"
505: cp $TMP1 $CUR
506: fi
507: fi
508:
509: # Check special files.
510: # Check system binaries.
511: #
512: # Create the mtree tree specifications using:
513: #
514: # mtree -cx -pDIR -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure
1.2 ! deraadt 515: # chown root.wheel DIR.secure
! 516: # chmod 600 DIR.secure
1.1 deraadt 517: #
518: # Note, this is not complete protection against Trojan horsed binaries, as
519: # the hacker can modify the tree specification to match the replaced binary.
520: # For details on really protecting yourself against modified binaries, see
521: # the mtree(8) manual page.
1.2 ! deraadt 522: if [ -d /etc/mtree ]; then
! 523: cd /etc/mtree
1.1 deraadt 524: mtree -e -p / -f /etc/mtree/special > $OUTPUT
525: if [ -s $OUTPUT ] ; then
526: printf "\nChecking special files and directories.\n"
527: cat $OUTPUT
528: fi
529:
530: > $OUTPUT
531: for file in *.secure; do
1.2 ! deraadt 532: [ $file = '*.secure' ] && continue
1.1 deraadt 533: tree=`sed -n -e '3s/.* //p' -e 3q $file`
534: mtree -f $file -p $tree > $TMP1
535: if [ -s $TMP1 ]; then
536: printf "\nChecking $tree:\n" >> $OUTPUT
537: cat $TMP1 >> $OUTPUT
538: fi
539: done
540: if [ -s $OUTPUT ] ; then
541: printf "\nChecking system binaries:\n"
542: cat $OUTPUT
543: fi
1.2 ! deraadt 544: else
! 545: echo /etc/mtree is missing
1.1 deraadt 546: fi
547:
548: # List of files that get backed up and checked for any modifications. Each
549: # file is expected to have two backups, /var/backups/file.{current,backup}.
550: # Any changes cause the files to rotate.
551: if [ -s /etc/changelist ] ; then
552: for file in `cat /etc/changelist`; do
553: CUR=/var/backups/`basename $file`.current
554: BACK=/var/backups/`basename $file`.backup
555: if [ -s $file ]; then
556: if [ -s $CUR ] ; then
557: diff $CUR $file > $OUTPUT
558: if [ -s $OUTPUT ] ; then
559: printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file
560: cat $OUTPUT
561: cp -p $CUR $BACK
562: cp -p $file $CUR
563: chown root.wheel $CUR $BACK
564: fi
565: else
566: cp -p $file $CUR
567: chown root.wheel $CUR
568: fi
569: fi
570: done
571: fi
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