Annotation of src/etc/security, Revision 1.13
1.1 deraadt 1: #!/bin/sh -
2: #
1.13 ! millert 3: # $OpenBSD: security,v 1.12 1996/11/23 19:10:43 millert Exp $
! 4: # from: @(#)security 8.1 (Berkeley) 6/9/93
1.1 deraadt 5: #
1.13 ! millert 6:
1.1 deraadt 7: PATH=/sbin:/usr/sbin:/bin:/usr/bin
8:
9: umask 077
10:
1.7 deraadt 11: DIR=/tmp/_secure$$
12: ERR=$DIR/_secure1
13: TMP1=$DIR/_secure2
14: TMP2=$DIR/_secure3
15: TMP3=$DIR/_secure4
16: LIST=$DIR/_secure5
17: OUTPUT=$DIR/_secure6
1.1 deraadt 18:
1.7 deraadt 19: if ! mkdir $DIR ; then
20: printf "tmp directory %s already exists, looks like:\n" $DIR
21: ls -alF $DIR
22: exit 1
23: fi
1.8 deraadt 24:
25: trap 'rm -rf $DIR' 0
1.1 deraadt 26:
27: # Check the master password file syntax.
28: MP=/etc/master.passwd
29: awk -F: '{
30: if ($0 ~ /^[ ]*$/) {
31: printf("Line %d is a blank line.\n", NR);
32: next;
33: }
34: if (NF != 10)
35: printf("Line %d has the wrong number of fields.\n", NR);
1.2 deraadt 36: if ($1 ~ /^[+-].*$/)
37: next;
38: if ($1 == "")
1.13 ! millert 39: printf("Line %d has an empty login field.\n", NR);
1.2 deraadt 40: else if ($1 !~ /^[A-Za-z0-9][A-Za-z0-9_-]*$/)
1.1 deraadt 41: printf("Login %s has non-alphanumeric characters.\n", $1);
42: if (length($1) > 8)
43: printf("Login %s has more than 8 characters.\n", $1);
44: if ($2 == "")
45: printf("Login %s has no password.\n", $1);
46: if (length($2) != 13 && ($10 ~ /.*sh$/ || $10 == ""))
47: printf("Login %s is off but still has a valid shell.\n", $1);
1.9 deraadt 48: if ($3 == 0 && $1 != "root")
1.1 deraadt 49: printf("Login %s has a user id of 0.\n", $1);
50: if ($3 < 0)
51: printf("Login %s has a negative user id.\n", $1);
52: if ($4 < 0)
53: printf("Login %s has a negative group id.\n", $1);
54: }' < $MP > $OUTPUT
55: if [ -s $OUTPUT ] ; then
56: printf "\nChecking the $MP file:\n"
57: cat $OUTPUT
58: fi
59:
60: awk -F: '{ print $1 }' $MP | sort | uniq -d > $OUTPUT
61: if [ -s $OUTPUT ] ; then
62: printf "\n$MP has duplicate user names.\n"
63: column $OUTPUT
64: fi
65:
1.9 deraadt 66: awk -F: '{ print $1 " " $3 }' $MP | sort -n +1 | tee $TMP1 |
1.1 deraadt 67: uniq -d -f 1 | awk '{ print $2 }' > $TMP2
68: if [ -s $TMP2 ] ; then
69: printf "\n$MP has duplicate user id's.\n"
70: while read uid; do
71: grep -w $uid $TMP1
72: done < $TMP2 | column
73: fi
74:
75: # Backup the master password file; a special case, the normal backup
76: # mechanisms also print out file differences and we don't want to do
77: # that because this file has encrypted passwords in it.
1.2 deraadt 78: if [ ! -d /var/backups ] ; then
79: mkdir /var/backups
80: chmod 755 /var/backups
81: fi
1.1 deraadt 82: CUR=/var/backups/`basename $MP`.current
83: BACK=/var/backups/`basename $MP`.backup
84: if [ -s $CUR ] ; then
85: if cmp -s $CUR $MP; then
86: :
87: else
88: cp -p $CUR $BACK
89: cp -p $MP $CUR
90: chown root.wheel $CUR
91: fi
92: else
93: cp -p $MP $CUR
94: chown root.wheel $CUR
95: fi
96:
97: # Check the group file syntax.
98: GRP=/etc/group
99: awk -F: '{
100: if ($0 ~ /^[ ]*$/) {
101: printf("Line %d is a blank line.\n", NR);
102: next;
103: }
1.2 deraadt 104: if ($1 ~ /^[+-].*$/)
105: next;
1.1 deraadt 106: if (NF != 4)
107: printf("Line %d has the wrong number of fields.\n", NR);
1.13 ! millert 108: if ($1 !~ /^[A-za-z0-9][A-za-z0-9_-]*$/)
1.1 deraadt 109: printf("Group %s has non-alphanumeric characters.\n", $1);
110: if (length($1) > 8)
111: printf("Group %s has more than 8 characters.\n", $1);
112: if ($3 !~ /[0-9]*/)
113: printf("Login %s has a negative group id.\n", $1);
114: }' < $GRP > $OUTPUT
115: if [ -s $OUTPUT ] ; then
116: printf "\nChecking the $GRP file:\n"
117: cat $OUTPUT
118: fi
119:
120: awk -F: '{ print $1 }' $GRP | sort | uniq -d > $OUTPUT
121: if [ -s $OUTPUT ] ; then
122: printf "\n$GRP has duplicate group names.\n"
123: column $OUTPUT
124: fi
125:
126: # Check for root paths, umask values in startup files.
127: # The check for the root paths is problematical -- it's likely to fail
128: # in other environments. Once the shells have been modified to warn
129: # of '.' in the path, the path tests should go away.
130: > $OUTPUT
131: rhome=/root
132: umaskset=no
133: list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login"
134: for i in $list ; do
135: if [ -f $i ] ; then
136: if egrep umask $i > /dev/null ; then
137: umaskset=yes
138: fi
139: egrep umask $i |
140: awk '$2 % 100 < 20 \
141: { print "Root umask is group writeable" }
142: $2 % 10 < 2 \
143: { print "Root umask is other writeable" }' >> $OUTPUT
144: /bin/csh -f -s << end-of-csh > /dev/null 2>&1
145: unset path
146: source $i
147: /bin/ls -ldgT \$path > $TMP1
148: end-of-csh
149: awk '{
150: if ($10 ~ /^\.$/) {
151: print "The root path includes .";
152: next;
153: }
154: }
155: $1 ~ /^d....w/ \
156: { print "Root path directory " $10 " is group writeable." } \
157: $1 ~ /^d.......w/ \
158: { print "Root path directory " $10 " is other writeable." }' \
159: < $TMP1 >> $OUTPUT
160: fi
161: done
162: if [ $umaskset = "no" -o -s $OUTPUT ] ; then
163: printf "\nChecking root csh paths, umask values:\n$list\n"
1.13 ! millert 164: if [ -s $OUTPUT ] ; then
1.1 deraadt 165: cat $OUTPUT
166: fi
167: if [ $umaskset = "no" ] ; then
168: printf "\nRoot csh startup files do not set the umask.\n"
169: fi
170: fi
171:
172: > $OUTPUT
173: rhome=/root
174: umaskset=no
175: list="${rhome}/.profile"
176: for i in $list; do
177: if [ -f $i ] ; then
178: if egrep umask $i > /dev/null ; then
179: umaskset=yes
180: fi
181: egrep umask $i |
182: awk '$2 % 100 < 20 \
183: { print "Root umask is group writeable" } \
184: $2 % 10 < 2 \
185: { print "Root umask is other writeable" }' >> $OUTPUT
186: /bin/sh << end-of-sh > /dev/null 2>&1
187: PATH=
188: . $i
189: list=\`echo \$PATH | /usr/bin/sed -e 's/:/ /g'\`
190: /bin/ls -ldgT \$list > $TMP1
191: end-of-sh
192: awk '{
193: if ($10 ~ /^\.$/) {
194: print "The root path includes .";
195: next;
196: }
197: }
198: $1 ~ /^d....w/ \
199: { print "Root path directory " $10 " is group writeable." } \
200: $1 ~ /^d.......w/ \
201: { print "Root path directory " $10 " is other writeable." }' \
202: < $TMP1 >> $OUTPUT
203:
204: fi
205: done
206: if [ $umaskset = "no" -o -s $OUTPUT ] ; then
207: printf "\nChecking root sh paths, umask values:\n$list\n"
1.13 ! millert 208: if [ -s $OUTPUT ] ; then
1.1 deraadt 209: cat $OUTPUT
210: fi
211: if [ $umaskset = "no" ] ; then
212: printf "\nRoot sh startup files do not set the umask.\n"
213: fi
214: fi
215:
216: # Root and uucp should both be in /etc/ftpusers.
217: if egrep root /etc/ftpusers > /dev/null ; then
218: :
219: else
220: printf "\nRoot not listed in /etc/ftpusers file.\n"
221: fi
222: if egrep uucp /etc/ftpusers > /dev/null ; then
223: :
224: else
225: printf "\nUucp not listed in /etc/ftpusers file.\n"
226: fi
227:
228: # Uudecode should not be in the /etc/aliases file.
229: if egrep 'uudecode|decode' /etc/aliases; then
230: printf "\nThere is an entry for uudecode in the /etc/aliases file.\n"
231: fi
232:
233: # Files that should not have + signs.
1.2 deraadt 234: list="/etc/hosts.equiv /etc/shosts.equiv /etc/hosts.lpd"
1.1 deraadt 235: for f in $list ; do
1.6 millert 236: if [ -s $f ] ; then
1.2 deraadt 237: awk '{
1.13 ! millert 238: if ($0 ~ /^\+@.*$/)
1.2 deraadt 239: next;
1.13 ! millert 240: if ($0 ~ /^\+.*$/)
1.2 deraadt 241: printf("\nPlus sign in %s file.\n", FILENAME);
242: }' $f
1.1 deraadt 243: fi
244: done
245:
1.13 ! millert 246: # Check for special users with .rhosts/.shosts files. Only root
! 247: # should have .rhosts/.shosts files. Also, .rhosts/.shosts
! 248: # files should not have plus signs.
1.9 deraadt 249: awk -F: '$1 != "root" && $1 !~ /^[+-].*$/ && \
1.1 deraadt 250: ($3 < 100 || $1 == "ftp" || $1 == "uucp") \
251: { print $1 " " $6 }' /etc/passwd |
252: while read uid homedir; do
1.2 deraadt 253: for j in .rhosts .shosts; do
254: if [ -f ${homedir}/$j ] ; then
255: rhost=`ls -ldgT ${homedir}/$j`
256: printf "$uid: $rhost\n"
257: fi
258: done
1.1 deraadt 259: done > $OUTPUT
260: if [ -s $OUTPUT ] ; then
1.2 deraadt 261: printf "\nChecking for special users with .rhosts/.shosts files.\n"
1.1 deraadt 262: cat $OUTPUT
263: fi
264:
265: awk -F: '{ print $1 " " $6 }' /etc/passwd | \
266: while read uid homedir; do
1.2 deraadt 267: for j in .rhosts .shosts; do
1.13 ! millert 268: if [ -s ${homedir}/$j ] ; then
1.2 deraadt 269: awk '{
270: if ($0 ~ /^+@.*$/ )
271: next;
1.4 deraadt 272: if ($0 ~ /^\+[ ]*$/ )
1.2 deraadt 273: printf("%s has + sign in it.\n",
1.13 ! millert 274: FILENAME);
1.2 deraadt 275: }' ${homedir}/$j
276: fi
277: done
1.1 deraadt 278: done > $OUTPUT
279: if [ -s $OUTPUT ] ; then
1.2 deraadt 280: printf "\nChecking .rhosts/.shosts files syntax.\n"
1.1 deraadt 281: cat $OUTPUT
282: fi
283:
284: # Check home directories. Directories should not be owned by someone else
285: # or writeable.
1.13 ! millert 286: awk -F: '{ if ($1 !~ /^[+-].*$/) print $1 " " $6 }' /etc/passwd | \
1.1 deraadt 287: while read uid homedir; do
288: if [ -d ${homedir}/ ] ; then
289: file=`ls -ldgT ${homedir}`
290: printf "$uid $file\n"
291: fi
292: done |
293: awk '$1 != $4 && $4 != "root" \
294: { print "user " $1 " home directory is owned by " $4 }
295: $2 ~ /^-....w/ \
296: { print "user " $1 " home directory is group writeable" }
297: $2 ~ /^-.......w/ \
298: { print "user " $1 " home directory is other writeable" }' > $OUTPUT
299: if [ -s $OUTPUT ] ; then
300: printf "\nChecking home directories.\n"
301: cat $OUTPUT
302: fi
303:
304: # Files that should not be owned by someone else or readable.
1.2 deraadt 305: list=".netrc .rhosts .shosts"
1.1 deraadt 306: awk -F: '{ print $1 " " $6 }' /etc/passwd | \
307: while read uid homedir; do
308: for f in $list ; do
309: file=${homedir}/${f}
310: if [ -f $file ] ; then
311: printf "$uid $f `ls -ldgT $file`\n"
312: fi
313: done
314: done |
315: awk '$1 != $5 && $5 != "root" \
316: { print "user " $1 " " $2 " file is owned by " $5 }
1.13 ! millert 317: $3 ~ /^-...r/ \
! 318: { print "user " $1 " " $2 " file is group readable" }
1.1 deraadt 319: $3 ~ /^-......r/ \
320: { print "user " $1 " " $2 " file is other readable" }
321: $3 ~ /^-....w/ \
322: { print "user " $1 " " $2 " file is group writeable" }
323: $3 ~ /^-.......w/ \
324: { print "user " $1 " " $2 " file is other writeable" }' > $OUTPUT
325:
326: # Files that should not be owned by someone else or writeable.
327: list=".bashrc .cshrc .emacs .exrc .forward .klogin .login .logout \
328: .profile .tcshrc"
329: awk -F: '{ print $1 " " $6 }' /etc/passwd | \
330: while read uid homedir; do
331: for f in $list ; do
332: file=${homedir}/${f}
333: if [ -f $file ] ; then
334: printf "$uid $f `ls -ldgT $file`\n"
335: fi
336: done
337: done |
338: awk '$1 != $5 && $5 != "root" \
339: { print "user " $1 " " $2 " file is owned by " $5 }
340: $3 ~ /^-....w/ \
341: { print "user " $1 " " $2 " file is group writeable" }
342: $3 ~ /^-.......w/ \
343: { print "user " $1 " " $2 " file is other writeable" }' >> $OUTPUT
344: if [ -s $OUTPUT ] ; then
345: printf "\nChecking dot files.\n"
346: cat $OUTPUT
347: fi
348:
349: # Mailboxes should be owned by user and unreadable.
350: ls -l /var/mail | sed 1d | \
351: awk '$3 != $9 \
352: { print "user " $9 " mailbox is owned by " $3 }
353: $1 != "-rw-------" \
354: { print "user " $9 " mailbox is " $1 ", group " $4 }' > $OUTPUT
355: if [ -s $OUTPUT ] ; then
356: printf "\nChecking mailbox ownership.\n"
357: cat $OUTPUT
358: fi
359:
1.13 ! millert 360: # File systems should not be globally exported.
! 361: if [ -s /etc/exports ] ; then
! 362: awk '{
! 363: if ($1 ~ /^#/)
1.1 deraadt 364: next;
1.13 ! millert 365: readonly = 0;
! 366: for (i = 2; i <= NF; ++i) {
! 367: if ($i ~ /-ro/)
! 368: readonly = 1;
! 369: else if ($i !~ /^-/)
! 370: next;
! 371: }
! 372: if (readonly)
! 373: print "File system " $1 " globally exported, read-only."
! 374: else
! 375: print "File system " $1 " globally exported, read-write."
! 376: }' < /etc/exports > $OUTPUT
! 377: if [ -s $OUTPUT ] ; then
! 378: printf "\nChecking for globally exported file systems.\n"
! 379: cat $OUTPUT
! 380: fi
1.1 deraadt 381: fi
382:
1.5 deraadt 383: # Display any changes in setuid/setgid files and devices.
384: pending="\nChecking setuid/setgid files and devices:\n"
1.1 deraadt 385: (find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \
1.13 ! millert 386: -o -fstype procfs \) -a -prune -o \
! 387: -type f -a \( -perm -u+s -o -perm -g+s \) -print0 -o \
! 388: ! -type d -a ! -type f -a ! -type l -a ! -type s -print0 | \
! 389: xargs -0 ls -ldgT | sort +9 > $LIST) 2> $OUTPUT
1.1 deraadt 390:
391: # Display any errors that occurred during system file walk.
392: if [ -s $OUTPUT ] ; then
1.2 deraadt 393: printf "${pending}Setuid/device find errors:\n"
394: pending=
1.1 deraadt 395: cat $OUTPUT
396: printf "\n"
397: fi
398:
1.12 millert 399: # Display any changes in the setuid/setgid file list.
1.13 ! millert 400: egrep -v '^[bc]' $LIST > $TMP1
1.1 deraadt 401: if [ -s $TMP1 ] ; then
402: # Check to make sure uudecode isn't setuid.
403: if grep -w uudecode $TMP1 > /dev/null ; then
1.2 deraadt 404: printf "${pending}\nUudecode is setuid.\n"
405: pending=
1.1 deraadt 406: fi
407:
408: CUR=/var/backups/setuid.current
409: BACK=/var/backups/setuid.backup
410:
411: if [ -s $CUR ] ; then
412: if cmp -s $CUR $TMP1 ; then
413: :
414: else
415: > $TMP2
1.13 ! millert 416: join -110 -210 -v2 $CUR $TMP1 > $OUTPUT
1.1 deraadt 417: if [ -s $OUTPUT ] ; then
1.2 deraadt 418: printf "${pending}Setuid additions:\n"
419: pending=
1.1 deraadt 420: tee -a $TMP2 < $OUTPUT
421: printf "\n"
422: fi
423:
1.13 ! millert 424: join -110 -210 -v1 $CUR $TMP1 > $OUTPUT
1.1 deraadt 425: if [ -s $OUTPUT ] ; then
1.2 deraadt 426: printf "${pending}Setuid deletions:\n"
427: pending=
1.1 deraadt 428: tee -a $TMP2 < $OUTPUT
429: printf "\n"
430: fi
431:
1.13 ! millert 432: sort +9 $TMP2 $CUR $TMP1 | \
1.1 deraadt 433: sed -e 's/[ ][ ]*/ /g' | uniq -u > $OUTPUT
434: if [ -s $OUTPUT ] ; then
1.2 deraadt 435: printf "${pending}Setuid changes:\n"
436: pending=
1.1 deraadt 437: column -t $OUTPUT
438: printf "\n"
439: fi
440:
441: cp $CUR $BACK
442: cp $TMP1 $CUR
443: fi
444: else
1.2 deraadt 445: printf "${pending}Setuid additions:\n"
446: pending=
1.1 deraadt 447: column -t $TMP1
448: printf "\n"
449: cp $TMP1 $CUR
450: fi
451: fi
452:
453: # Check for block and character disk devices that are readable or writeable
454: # or not owned by root.operator.
455: >$TMP1
1.13 ! millert 456: DISKLIST="ccd dk fd hd hk hp jb kra ra rb rd rl rx rz sd up vnd wd xd"
1.1 deraadt 457: for i in $DISKLIST; do
1.11 tholo 458: egrep "^b.*/${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1
459: egrep "^c.*/r${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1
1.1 deraadt 460: done
461:
462: awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \
463: { printf("Disk %s is user %s, group %s, permissions %s.\n", \
464: $11, $3, $4, $1); }' < $TMP1 > $OUTPUT
465: if [ -s $OUTPUT ] ; then
466: printf "\nChecking disk ownership and permissions.\n"
467: cat $OUTPUT
468: printf "\n"
469: fi
470:
471: # Display any changes in the device file list.
472: egrep '^[bc]' $LIST | sort +10 > $TMP1
473: if [ -s $TMP1 ] ; then
474: CUR=/var/backups/device.current
475: BACK=/var/backups/device.backup
476:
477: if [ -s $CUR ] ; then
478: if cmp -s $CUR $TMP1 ; then
479: :
480: else
481: > $TMP2
482: join -111 -211 -v2 $CUR $TMP1 > $OUTPUT
483: if [ -s $OUTPUT ] ; then
484: printf "Device additions:\n"
485: tee -a $TMP2 < $OUTPUT
486: printf "\n"
487: fi
488:
489: join -111 -211 -v1 $CUR $TMP1 > $OUTPUT
490: if [ -s $OUTPUT ] ; then
491: printf "Device deletions:\n"
492: tee -a $TMP2 < $OUTPUT
493: printf "\n"
494: fi
495:
496: # Report any block device change. Ignore character
497: # devices, only the name is significant.
498: cat $TMP2 $CUR $TMP1 | \
499: sed -e '/^c/d' | \
500: sort +10 | \
501: sed -e 's/[ ][ ]*/ /g' | \
502: uniq -u > $OUTPUT
503: if [ -s $OUTPUT ] ; then
504: printf "Block device changes:\n"
505: column -t $OUTPUT
506: printf "\n"
507: fi
508:
509: cp $CUR $BACK
510: cp $TMP1 $CUR
511: fi
512: else
513: printf "Device additions:\n"
514: column -t $TMP1
515: printf "\n"
516: cp $TMP1 $CUR
517: fi
518: fi
519:
520: # Check special files.
521: # Check system binaries.
522: #
523: # Create the mtree tree specifications using:
524: #
525: # mtree -cx -pDIR -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure
1.2 deraadt 526: # chown root.wheel DIR.secure
527: # chmod 600 DIR.secure
1.1 deraadt 528: #
529: # Note, this is not complete protection against Trojan horsed binaries, as
530: # the hacker can modify the tree specification to match the replaced binary.
531: # For details on really protecting yourself against modified binaries, see
532: # the mtree(8) manual page.
1.13 ! millert 533: if [ -d /etc/mtree ] ; then
1.2 deraadt 534: cd /etc/mtree
1.1 deraadt 535: mtree -e -p / -f /etc/mtree/special > $OUTPUT
536: if [ -s $OUTPUT ] ; then
537: printf "\nChecking special files and directories.\n"
538: cat $OUTPUT
539: fi
540:
541: > $OUTPUT
542: for file in *.secure; do
1.2 deraadt 543: [ $file = '*.secure' ] && continue
1.1 deraadt 544: tree=`sed -n -e '3s/.* //p' -e 3q $file`
545: mtree -f $file -p $tree > $TMP1
1.13 ! millert 546: if [ -s $TMP1 ] ; then
1.1 deraadt 547: printf "\nChecking $tree:\n" >> $OUTPUT
548: cat $TMP1 >> $OUTPUT
549: fi
550: done
551: if [ -s $OUTPUT ] ; then
552: printf "\nChecking system binaries:\n"
553: cat $OUTPUT
554: fi
1.2 deraadt 555: else
556: echo /etc/mtree is missing
1.1 deraadt 557: fi
558:
559: # List of files that get backed up and checked for any modifications. Each
560: # file is expected to have two backups, /var/backups/file.{current,backup}.
561: # Any changes cause the files to rotate.
562: if [ -s /etc/changelist ] ; then
563: for file in `cat /etc/changelist`; do
564: CUR=/var/backups/`basename $file`.current
565: BACK=/var/backups/`basename $file`.backup
1.13 ! millert 566: if [ -s $file ] ; then
1.1 deraadt 567: if [ -s $CUR ] ; then
568: diff $CUR $file > $OUTPUT
569: if [ -s $OUTPUT ] ; then
570: printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file
571: cat $OUTPUT
572: cp -p $CUR $BACK
573: cp -p $file $CUR
574: chown root.wheel $CUR $BACK
575: fi
576: else
577: cp -p $file $CUR
578: chown root.wheel $CUR
579: fi
580: fi
581: done
582: fi
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