security revision 1.27
1 #!/bin/sh - 2 # 3 # $NetBSD: security,v 1.27 1997/08/22 09:40:17 lukem Exp $ 4 # from: @(#)security 8.1 (Berkeley) 6/9/93 5 # 6 7 PATH=/sbin:/usr/sbin:/bin:/usr/bin 8 9 umask 077 10 11 if [ -s /etc/security.conf ]; then 12 . /etc/security.conf 13 fi 14 15 SECUREDIR=/tmp/_securedir.$$ 16 if ! mkdir $SECUREDIR; then 17 echo can not create $SECUREDIR. 18 exit 1 19 fi 20 21 if ! cd $SECUREDIR; then 22 echo can not chdir to $SECUREDIR. 23 exit 1 24 fi 25 26 ERR=secure1.$$ 27 TMP1=secure2.$$ 28 TMP2=secure3.$$ 29 MPUID=secure4.$$ 30 MPPATH=secure5.$$ 31 LIST=secure6.$$ 32 OUTPUT=secure7.$$ 33 34 trap '/bin/rm -rf $SECUREDIR ; exit 0' 0 2 3 35 36 MP=/etc/master.passwd 37 38 # these is used several times. 39 awk -F: '{ print $1 " " $3 }' $MP | sort -k2n > $MPUID 40 awk -F: '{ print $1 " " $9 }' $MP | sort -k2 > $MPPATH 41 42 # Check the master password file syntax. 43 if [ "$check_passwd" = YES ]; then 44 awk ' 45 BEGIN { 46 while ( getline < "/etc/shells" > 0 ) { 47 if ($LINE ~ /^\#/ || $LINE ~ /^$/ ) 48 continue; 49 shells[$1]++; 50 } 51 FS=":"; 52 } 53 54 { 55 if ($0 ~ /^[ ]*$/) { 56 printf "Line %d is a blank line.\n", NR; 57 next; 58 } 59 if (NF != 10) 60 printf "Line %d has the wrong number of fields.\n", NR; 61 if ($1 !~ /^[A-Za-z0-9]*$/) 62 printf "Login %s has non-alphanumeric characters.\n", 63 $1; 64 if (length($1) > 8) 65 printf "Login %s has more than 8 characters.\n", $1; 66 if ($2 == "") 67 printf "Login %s has no password.\n", $1; 68 if (length($2) != 13 && $2 != "") { 69 if ($10 == "" || shells[$10]) 70 printf "Login %s is off but still has a valid shell (%s)\n", 71 $1, $10; 72 } else if (! shells[$10]) 73 printf "Login %s does not have a valid shell (%s)\n", 74 $1, $10; 75 if ($3 == 0 && $1 != "root" && $1 != "toor") 76 printf "Login %s has a user id of 0.\n", $1; 77 if ($3 < 0) 78 printf "Login %s has a negative user id.\n", $1; 79 if ($4 < 0) 80 printf "Login %s has a negative group id.\n", $1; 81 }' < $MP > $OUTPUT 82 if [ -s $OUTPUT ] ; then 83 printf "\nChecking the $MP file:\n" 84 cat $OUTPUT 85 fi 86 87 awk -F: '{ print $1 }' $MP | sort | uniq -d > $OUTPUT 88 if [ -s $OUTPUT ] ; then 89 printf "\n$MP has duplicate user names.\n" 90 column $OUTPUT 91 fi 92 93 < $MPUID uniq -d -f 1 | awk '{ print $2 }' > $TMP2 94 if [ -s $TMP2 ] ; then 95 printf "\n$MP has duplicate user id's.\n" 96 while read uid; do 97 grep -w $uid $MPUID 98 done < $TMP2 | column 99 fi 100 fi 101 102 # Backup the master password file; a special case, the normal backup 103 # mechanisms also print out file differences and we don't want to do 104 # that because this file has encrypted passwords in it. 105 CUR=/var/backups/`basename $MP`.current 106 BACK=/var/backups/`basename $MP`.backup 107 if [ -s $CUR ] ; then 108 if cmp -s $CUR $MP; then 109 : 110 else 111 cp -p $CUR $BACK 112 cp -p $MP $CUR 113 chown root.wheel $CUR 114 fi 115 else 116 cp -p $MP $CUR 117 chown root.wheel $CUR 118 fi 119 120 # Check the group file syntax. 121 if [ "$check_group" = YES ]; then 122 GRP=/etc/group 123 awk -F: '{ 124 if ($0 ~ /^[ ]*$/) { 125 printf "Line %d is a blank line.\n", NR; 126 next; 127 } 128 if (NF != 4) 129 printf "Line %d has the wrong number of fields.\n", NR; 130 if ($1 !~ /^[A-za-z0-9]*$/) 131 printf "Group %s has non-alphanumeric characters.\n", 132 $1; 133 if (length($1) > 8) 134 printf "Group %s has more than 8 characters.\n", $1; 135 if ($3 !~ /[0-9]*/) 136 printf "Login %s has a negative group id.\n", $1; 137 }' < $GRP > $OUTPUT 138 if [ -s $OUTPUT ] ; then 139 printf "\nChecking the $GRP file:\n" 140 cat $OUTPUT 141 fi 142 143 awk -F: '{ print $1 }' $GRP | sort | uniq -d > $OUTPUT 144 if [ -s $OUTPUT ] ; then 145 printf "\n$GRP has duplicate group names.\n" 146 column $OUTPUT 147 fi 148 fi 149 150 # Check for root paths, umask values in startup files. 151 # The check for the root paths is problematical -- it's likely to fail 152 # in other environments. Once the shells have been modified to warn 153 # of '.' in the path, the path tests should go away. 154 if [ "$check_rootdotfiles" = YES ]; then 155 cp /dev/null $OUTPUT 156 rhome=`csh -fc "echo ~root"` 157 umaskset=no 158 list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login" 159 for i in $list ; do 160 if [ -f $i ] ; then 161 if egrep umask $i > /dev/null ; then 162 umaskset=yes 163 fi 164 egrep umask $i | 165 awk '$2 % 100 < 20 \ 166 { print "\tRoot umask is group writeable" } 167 $2 % 10 < 2 \ 168 { print "\tRoot umask is other writeable" }' \ 169 >> $OUTPUT 170 SAVE_PATH=$PATH 171 unset PATH 172 /bin/csh -f -s << end-of-csh > /dev/null 2>&1 173 source $i 174 /bin/ls -ldgT \$path > $TMP1 175 end-of-csh 176 PATH=$SAVE_PATH 177 awk '{ 178 if ($10 ~ /^\.$/) { 179 print "\tThe root path includes ."; 180 next; 181 } 182 } 183 $1 ~ /^d....w/ \ 184 { print "\tRoot path directory " $10 " is group writeable." } \ 185 $1 ~ /^d.......w/ \ 186 { print "\tRoot path directory " $10 " is other writeable." }' \ 187 < $TMP1 >> $OUTPUT 188 fi 189 done 190 if [ $umaskset = "no" -o -s $OUTPUT ] ; then 191 printf "\nChecking root csh paths, umask values:\n$list\n\n" 192 if [ -s $OUTPUT ]; then 193 cat $OUTPUT 194 fi 195 if [ $umaskset = "no" ] ; then 196 printf "\tRoot csh startup files do not set the umask.\n" 197 fi 198 fi 199 200 cp /dev/null $OUTPUT 201 rhome=/root 202 umaskset=no 203 list="/etc/profile ${rhome}/.profile" 204 for i in $list; do 205 if [ -f $i ] ; then 206 if egrep umask $i > /dev/null ; then 207 umaskset=yes 208 fi 209 egrep umask $i | 210 awk '$2 % 100 < 20 \ 211 { print "\tRoot umask is group writeable" } \ 212 $2 % 10 < 2 \ 213 { print "\tRoot umask is other writeable" }' \ 214 >> $OUTPUT 215 SAVE_PATH=$PATH 216 unset PATH 217 /bin/sh << end-of-sh > /dev/null 2>&1 218 . $i 219 list=\`echo \$PATH | /usr/bin/sed -e \ 220 's/^:/.:/;s/:$/:./;s/::/:.:/g;s/:/ /g'\` 221 /bin/ls -ldgT \$list > $TMP1 222 end-of-sh 223 PATH=$SAVE_PATH 224 awk '{ 225 if ($10 ~ /^\.$/) { 226 print "\tThe root path includes ."; 227 next; 228 } 229 } 230 $1 ~ /^d....w/ \ 231 { print "\tRoot path directory " $10 " is group writeable." } \ 232 $1 ~ /^d.......w/ \ 233 { print "\tRoot path directory " $10 " is other writeable." }' \ 234 < $TMP1 >> $OUTPUT 235 236 fi 237 done 238 if [ $umaskset = "no" -o -s $OUTPUT ] ; then 239 printf "\nChecking root sh paths, umask values:\n$list\n" 240 if [ -s $OUTPUT ]; then 241 cat $OUTPUT 242 fi 243 if [ $umaskset = "no" ] ; then 244 printf "\tRoot sh startup files do not set the umask.\n" 245 fi 246 fi 247 fi 248 249 # Root and uucp should both be in /etc/ftpusers. 250 # XXX This should be updated to support the new format... 251 if [ "$check_ftpusers" = YES ]; then 252 list="root uucp" 253 for i in $list; do 254 if ! egrep "^$i$" /etc/ftpusers > /dev/null ; then 255 printf "\n$i is not listed in /etc/ftpusers file.\n" 256 fi 257 done 258 fi 259 260 # Uudecode should not be in the /etc/aliases file. 261 if [ "$check_aliases" = YES ]; then 262 if egrep '^[^#]*(uudecode|decode).*\|' /etc/aliases; then 263 printf "\nEntry for uudecode in /etc/aliases file.\n" 264 fi 265 fi 266 267 # Files that should not have + signs. 268 if [ "$check_rhosts" = YES ]; then 269 list="/etc/hosts.equiv /etc/hosts.lpd" 270 for f in $list ; do 271 if [ -f $f ] && egrep '\+' $f > /dev/null ; then 272 printf "\nPlus sign in $f file.\n" 273 fi 274 done 275 276 # Check for special users with .rhosts files. Only root and toor should 277 # have .rhosts files. Also, .rhosts files should not have plus signs. 278 awk -F: '$1 != "root" && $1 != "toor" && \ 279 ($3 < 100 || $1 == "ftp" || $1 == "uucp") \ 280 { print $1 " " $9 }' $MP | 281 sort -k2 | 282 while read uid homedir; do 283 if [ -f ${homedir}/.rhosts ] ; then 284 rhost=`ls -ldgT ${homedir}/.rhosts` 285 printf "$uid: $rhost\n" 286 fi 287 done > $OUTPUT 288 if [ -s $OUTPUT ] ; then 289 printf "\nChecking for special users with .rhosts files.\n" 290 cat $OUTPUT 291 fi 292 293 while read uid homedir; do 294 if [ -f ${homedir}/.rhosts ] && \ 295 egrep '\+' ${homedir}/.rhosts > /dev/null ; then 296 printf "$uid: + in .rhosts file.\n" 297 fi 298 done < $MPPATH > $OUTPUT 299 if [ -s $OUTPUT ] ; then 300 printf "\nChecking .rhosts files syntax.\n" 301 cat $OUTPUT 302 fi 303 fi 304 305 # Check home directories. Directories should not be owned by someone else 306 # or writeable. 307 if [ "$check_homes" = YES ]; then 308 while read uid homedir; do 309 if [ -d ${homedir}/ ] ; then 310 file=`ls -ldgT ${homedir}` 311 printf "$uid $file\n" 312 fi 313 done < $MPPATH | 314 awk '$1 != $4 && $4 != "root" \ 315 { print "user " $1 " home directory is owned by " $4 } 316 $2 ~ /^-....w/ \ 317 { print "user " $1 " home directory is group writeable" } 318 $2 ~ /^-.......w/ \ 319 { print "user " $1 " home directory is other writeable" }' \ 320 > $OUTPUT 321 if [ -s $OUTPUT ] ; then 322 printf "\nChecking home directories.\n" 323 cat $OUTPUT 324 fi 325 326 # Files that should not be owned by someone else or readable. 327 list=".Xauthority .netrc" 328 while read uid homedir; do 329 for f in $list ; do 330 file=${homedir}/${f} 331 if [ -f $file ] ; then 332 printf "$uid $f `ls -ldgT $file`\n" 333 fi 334 done 335 done < $MPPATH | 336 awk '$1 != $5 && $5 != "root" \ 337 { print "user " $1 " " $2 " file is owned by " $5 } 338 $3 ~ /^-...r/ \ 339 { print "user " $1 " " $2 " file is group readable" } 340 $3 ~ /^-......r/ \ 341 { print "user " $1 " " $2 " file is other readable" } 342 $3 ~ /^-....w/ \ 343 { print "user " $1 " " $2 " file is group writeable" } 344 $3 ~ /^-.......w/ \ 345 { print "user " $1 " " $2 " file is other writeable" }' \ 346 > $OUTPUT 347 348 # Files that should not be owned by someone else or writeable. 349 list=".bash_history .bash_login .bash_logout .bash_profile .bashrc \ 350 .cshrc .emacs .exrc .forward .history .klogin .login .logout \ 351 .profile .qmail .rc_history .rhosts .tcshrc .twmrc .xinitrc \ 352 .xsession" 353 while read uid homedir; do 354 for f in $list ; do 355 file=${homedir}/${f} 356 if [ -f $file ] ; then 357 printf "$uid $f `ls -ldgT $file`\n" 358 fi 359 done 360 done < $MPPATH | 361 awk '$1 != $5 && $5 != "root" \ 362 { print "user " $1 " " $2 " file is owned by " $5 } 363 $3 ~ /^-....w/ \ 364 { print "user " $1 " " $2 " file is group writeable" } 365 $3 ~ /^-.......w/ \ 366 { print "user " $1 " " $2 " file is other writeable" }' \ 367 >> $OUTPUT 368 if [ -s $OUTPUT ] ; then 369 printf "\nChecking dot files.\n" 370 cat $OUTPUT 371 fi 372 fi 373 374 # Mailboxes should be owned by user and unreadable. 375 if [ "$check_varmail" = YES ]; then 376 ls -l /var/mail | sed 1d | \ 377 awk '$3 != $9 \ 378 { print "user " $9 " mailbox is owned by " $3 } 379 $1 != "-rw-------" \ 380 { print "user " $9 " mailbox is " $1 ", group " $4 }' > $OUTPUT 381 if [ -s $OUTPUT ] ; then 382 printf "\nChecking mailbox ownership.\n" 383 cat $OUTPUT 384 fi 385 fi 386 387 if [ "$check_nfs" = YES ]; then 388 if [ -f /etc/exports ]; then 389 # File systems should not be globally exported. 390 awk '{ 391 # ignore comments and blank lines 392 if ($LINE ~ /^\#/ || $LINE ~ /^$/ ) 393 next; 394 395 readonly = 0; 396 for (i = 2; i <= NF; ++i) { 397 if ($i ~ /-ro/) 398 readonly = 1; 399 else if ($i !~ /^-/) 400 next; 401 } 402 if (readonly) 403 print "File system " $1 " globally exported, read-only." 404 else 405 print "File system " $1 " globally exported, read-write." 406 }' < /etc/exports > $OUTPUT 407 if [ -s $OUTPUT ] ; then 408 printf "\nChecking for globally exported file systems.\n" 409 cat $OUTPUT 410 fi 411 fi 412 fi 413 414 # Display any changes in setuid files and devices. 415 if [ "$check_devices" = YES ]; then 416 printf "\nChecking setuid files and devices:\n" 417 (find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \ 418 -o -fstype procfs \) -a -prune -o \ 419 \( \( -perm -u+s -a ! -type d \) -o \ 420 \( -perm -g+s -a ! -type d \) -o \ 421 -type b -o -type c \) -print0 | \ 422 xargs -0 ls -ldgTq | sort +9 > $LIST) 2> $OUTPUT 423 424 # Display any errors that occurred during system file walk. 425 if [ -s $OUTPUT ] ; then 426 printf "Setuid/device find errors:\n" 427 cat $OUTPUT 428 printf "\n" 429 fi 430 431 # Display any changes in the setuid file list. 432 egrep -v '^[bc]' $LIST > $TMP1 433 if [ -s $TMP1 ] ; then 434 # Check to make sure uudecode isn't setuid. 435 if grep -w uudecode $TMP1 > /dev/null ; then 436 printf "\nUudecode is setuid.\n" 437 fi 438 439 CUR=/var/backups/setuid.current 440 BACK=/var/backups/setuid.backup 441 442 if [ -s $CUR ] ; then 443 if cmp -s $CUR $TMP1 ; then 444 : 445 else 446 > $TMP2 447 join -110 -210 -v2 $CUR $TMP1 > $OUTPUT 448 if [ -s $OUTPUT ] ; then 449 printf "Setuid additions:\n" 450 tee -a $TMP2 < $OUTPUT 451 printf "\n" 452 fi 453 454 join -110 -210 -v1 $CUR $TMP1 > $OUTPUT 455 if [ -s $OUTPUT ] ; then 456 printf "Setuid deletions:\n" 457 tee -a $TMP2 < $OUTPUT 458 printf "\n" 459 fi 460 461 sort -k10 $TMP2 $CUR $TMP1 | \ 462 sed -e 's/[ ][ ]*/ /g' | \ 463 uniq -u > $OUTPUT 464 if [ -s $OUTPUT ] ; then 465 printf "Setuid changes:\n" 466 column -t $OUTPUT 467 printf "\n" 468 fi 469 470 cp $CUR $BACK 471 cp $TMP1 $CUR 472 fi 473 else 474 printf "Setuid additions:\n" 475 column -t $TMP1 476 printf "\n" 477 cp $TMP1 $CUR 478 fi 479 fi 480 481 # Check for block and character disk devices that are readable or 482 # writeable or not owned by root.operator. 483 >$TMP1 484 DISKLIST="acd ccd cd ch fd hk hp mcd md ra rb rd rl rx rz \ 485 sd se ss tz uk up vnd wd xd xy" 486 # DISKLIST="$DISKLIST ct mt st wt" 487 for i in $DISKLIST; do 488 egrep "^b.*/${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1 489 egrep "^c.*/r${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1 490 done 491 492 awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \ 493 { printf "Disk %s is user %s, group %s, permissions %s.\n", \ 494 $11, $3, $4, $1; }' < $TMP1 > $OUTPUT 495 if [ -s $OUTPUT ] ; then 496 printf "\nChecking disk ownership and permissions.\n" 497 cat $OUTPUT 498 printf "\n" 499 fi 500 501 # Display any changes in the device file list. 502 egrep '^[bc]' $LIST | sort -k11 > $TMP1 503 if [ -s $TMP1 ] ; then 504 CUR=/var/backups/device.current 505 BACK=/var/backups/device.backup 506 507 if [ -s $CUR ] ; then 508 if cmp -s $CUR $TMP1 ; then 509 : 510 else 511 > $TMP2 512 join -111 -211 -v2 $CUR $TMP1 > $OUTPUT 513 if [ -s $OUTPUT ] ; then 514 printf "Device additions:\n" 515 tee -a $TMP2 < $OUTPUT 516 printf "\n" 517 fi 518 519 join -111 -211 -v1 $CUR $TMP1 > $OUTPUT 520 if [ -s $OUTPUT ] ; then 521 printf "Device deletions:\n" 522 tee -a $TMP2 < $OUTPUT 523 printf "\n" 524 fi 525 526 # Report any block device change. Ignore 527 # character devices, only the name is 528 # significant. 529 cat $TMP2 $CUR $TMP1 | \ 530 sed -e '/^c/d' | \ 531 sort -k11 | \ 532 sed -e 's/[ ][ ]*/ /g' | \ 533 uniq -u > $OUTPUT 534 if [ -s $OUTPUT ] ; then 535 printf "Block device changes:\n" 536 column -t $OUTPUT 537 printf "\n" 538 fi 539 540 cp $CUR $BACK 541 cp $TMP1 $CUR 542 fi 543 else 544 printf "Device additions:\n" 545 column -t $TMP1 546 printf "\n" 547 cp $TMP1 $CUR 548 fi 549 fi 550 fi 551 552 # Check special files. 553 # Check system binaries. 554 # 555 # Create the mtree tree specifications using: 556 # 557 # mtree -cx -pDIR -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure 558 # chown root.wheel DIR.secure 559 # chmod 600 DIR.secure 560 # 561 # Note, this is not complete protection against Trojan horsed binaries, as 562 # the hacker can modify the tree specification to match the replaced binary. 563 # For details on really protecting yourself against modified binaries, see 564 # the mtree(8) manual page. 565 if [ "$check_mtree" = YES ]; then 566 mtree -e -p / -f /etc/mtree/special > $OUTPUT 567 if [ -s $OUTPUT ]; then 568 printf "\nChecking special files and directories.\n" 569 cat $OUTPUT 570 fi 571 572 > $OUTPUT 573 for file in /etc/mtree/*.secure; do 574 [ $file = '/etc/mtree/*.secure' ] && continue 575 tree=`sed -n -e '3s/.* //p' -e 3q $file` 576 mtree -f $file -p $tree > $TMP1 577 if [ -s $TMP1 ]; then 578 printf "\nChecking $tree:\n" >> $OUTPUT 579 cat $TMP1 >> $OUTPUT 580 fi 581 done 582 if [ -s $OUTPUT ]; then 583 printf "\nChecking system binaries:\n" 584 cat $OUTPUT 585 fi 586 fi 587 588 # List of files that get backed up and checked for any modifications. Each 589 # file is expected to have two backups, /var/backups/file.{current,backup}. 590 # Any changes cause the files to rotate. 591 if [ "$check_changelist" = YES ] && [ -s /etc/changelist ] ; then 592 for file in `egrep -v "^#|$MP" /etc/changelist`; do 593 CUR=/var/backups/`basename $file`.current 594 BACK=/var/backups/`basename $file`.backup 595 if [ -s $file ]; then 596 if [ -s $CUR ] ; then 597 diff $CUR $file > $OUTPUT 598 if [ -s $OUTPUT ] ; then 599 printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file 600 cat $OUTPUT 601 cp -p $CUR $BACK 602 cp -p $file $CUR 603 chown root.wheel $CUR $BACK 604 fi 605 else 606 cp -p $file $CUR 607 chown root.wheel $CUR 608 fi 609 fi 610 done 611 fi 612
Indexes created Tue Sep 30 11:09:46 GMT 2025