security revision 1.21
1 #!/bin/sh - 2 # 3 # $NetBSD: security,v 1.21 1997/04/21 17:38:39 mycroft 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 TMP3=secure4.$$ 30 LIST=secure5.$$ 31 OUTPUT=secure6.$$ 32 33 trap 'rm -rf $SECUREDIR' 0 34 35 MP=/etc/master.passwd 36 37 # this is used several times. 38 awk -F: '{ print $1 " " $3 }' $MP | sort -k2n > $TMP1 39 40 # Check the master password file syntax. 41 if [ "$check_passwd" = YES ]; then 42 awk -F: '{ 43 if ($0 ~ /^[ ]*$/) { 44 printf("Line %d is a blank line.\n", NR); 45 next; 46 } 47 if (NF != 10) 48 printf("Line %d has the wrong number of fields.\n", NR); 49 if ($1 !~ /^[A-Za-z0-9]*$/) 50 printf("Login %s has non-alphanumeric characters.\n", $1); 51 if (length($1) > 8) 52 printf("Login %s has more than 8 characters.\n", $1); 53 if ($2 == "") 54 printf("Login %s has no password.\n", $1); 55 if (length($2) != 13 && $2 != "" && ($10 ~ /.*sh$/ || $10 == "")) 56 printf("Login %s is off but still has a valid shell.\n", $1); 57 if ($3 == 0 && $1 != "root" && $1 != "toor") 58 printf("Login %s has a user id of 0.\n", $1); 59 if ($3 < 0) 60 printf("Login %s has a negative user id.\n", $1); 61 if ($4 < 0) 62 printf("Login %s has a negative group id.\n", $1); 63 }' < $MP > $OUTPUT 64 if [ -s $OUTPUT ] ; then 65 printf "\nChecking the $MP file:\n" 66 cat $OUTPUT 67 fi 68 69 awk -F: '{ print $1 }' $MP | sort | uniq -d > $OUTPUT 70 if [ -s $OUTPUT ] ; then 71 printf "\n$MP has duplicate user names.\n" 72 column $OUTPUT 73 fi 74 75 < $TMP1 uniq -d -f 1 | awk '{ print $2 }' > $TMP2 76 if [ -s $TMP2 ] ; then 77 printf "\n$MP has duplicate user id's.\n" 78 while read uid; do 79 grep -w $uid $TMP1 80 done < $TMP2 | column 81 fi 82 fi 83 84 # Backup the master password file; a special case, the normal backup 85 # mechanisms also print out file differences and we don't want to do 86 # that because this file has encrypted passwords in it. 87 CUR=/var/backups/`basename $MP`.current 88 BACK=/var/backups/`basename $MP`.backup 89 if [ -s $CUR ] ; then 90 if cmp -s $CUR $MP; then 91 : 92 else 93 cp -p $CUR $BACK 94 cp -p $MP $CUR 95 chown root.wheel $CUR 96 fi 97 else 98 cp -p $MP $CUR 99 chown root.wheel $CUR 100 fi 101 102 # Check the group file syntax. 103 if [ "$check_group" = YES ]; then 104 GRP=/etc/group 105 awk -F: '{ 106 if ($0 ~ /^[ ]*$/) { 107 printf("Line %d is a blank line.\n", NR); 108 next; 109 } 110 if (NF != 4) 111 printf("Line %d has the wrong number of fields.\n", NR); 112 if ($1 !~ /^[A-za-z0-9]*$/) 113 printf("Group %s has non-alphanumeric characters.\n", $1); 114 if (length($1) > 8) 115 printf("Group %s has more than 8 characters.\n", $1); 116 if ($3 !~ /[0-9]*/) 117 printf("Login %s has a negative group id.\n", $1); 118 }' < $GRP > $OUTPUT 119 if [ -s $OUTPUT ] ; then 120 printf "\nChecking the $GRP file:\n" 121 cat $OUTPUT 122 fi 123 124 awk -F: '{ print $1 }' $GRP | sort | uniq -d > $OUTPUT 125 if [ -s $OUTPUT ] ; then 126 printf "\n$GRP has duplicate group names.\n" 127 column $OUTPUT 128 fi 129 fi 130 131 # Check for root paths, umask values in startup files. 132 # The check for the root paths is problematical -- it's likely to fail 133 # in other environments. Once the shells have been modified to warn 134 # of '.' in the path, the path tests should go away. 135 if [ "$check_rootdotfiles" = YES ]; then 136 cp /dev/null $OUTPUT 137 rhome=`csh -fc "echo ~root"` 138 umaskset=no 139 list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login" 140 for i in $list ; do 141 if [ -f $i ] ; then 142 if egrep umask $i > /dev/null ; then 143 umaskset=yes 144 fi 145 egrep umask $i | 146 awk '$2 % 100 < 20 \ 147 { print "Root umask is group writeable" } 148 $2 % 10 < 2 \ 149 { print "Root umask is other writeable" }' >> $OUTPUT 150 /bin/csh -f -s << end-of-csh > /dev/null 2>&1 151 unset path 152 source $i 153 /bin/ls -ldgT \$path > $TMP1 154 end-of-csh 155 awk '{ 156 if ($10 ~ /^\.$/) { 157 print "The root path includes ."; 158 next; 159 } 160 } 161 $1 ~ /^d....w/ \ 162 { print "Root path directory " $10 " is group writeable." } \ 163 $1 ~ /^d.......w/ \ 164 { print "Root path directory " $10 " is other writeable." }' \ 165 < $TMP1 >> $OUTPUT 166 fi 167 done 168 if [ $umaskset = "no" -o -s $OUTPUT ] ; then 169 printf "\nChecking root csh paths, umask values:\n$list\n" 170 if [ -s $OUTPUT ]; then 171 cat $OUTPUT 172 fi 173 if [ $umaskset = "no" ] ; then 174 printf "\nRoot csh startup files do not set the umask.\n" 175 fi 176 fi 177 178 cp /dev/null $OUTPUT 179 rhome=/root 180 umaskset=no 181 list="${rhome}/.profile" 182 for i in $list; do 183 if [ -f $i ] ; then 184 if egrep umask $i > /dev/null ; then 185 umaskset=yes 186 fi 187 egrep umask $i | 188 awk '$2 % 100 < 20 \ 189 { print "Root umask is group writeable" } \ 190 $2 % 10 < 2 \ 191 { print "Root umask is other writeable" }' >> $OUTPUT 192 /bin/sh << end-of-sh > /dev/null 2>&1 193 PATH= 194 . $i 195 list=\`echo \$PATH | /usr/bin/sed -e 's/:/ /g'\` 196 /bin/ls -ldgT \$list > $TMP1 197 end-of-sh 198 awk '{ 199 if ($10 ~ /^\.$/) { 200 print "The root path includes ."; 201 next; 202 } 203 } 204 $1 ~ /^d....w/ \ 205 { print "Root path directory " $10 " is group writeable." } \ 206 $1 ~ /^d.......w/ \ 207 { print "Root path directory " $10 " is other writeable." }' \ 208 < $TMP1 >> $OUTPUT 209 210 fi 211 done 212 if [ $umaskset = "no" -o -s $OUTPUT ] ; then 213 printf "\nChecking root sh paths, umask values:\n$list\n" 214 if [ -s $OUTPUT ]; then 215 cat $OUTPUT 216 fi 217 if [ $umaskset = "no" ] ; then 218 printf "\nRoot sh startup files do not set the umask.\n" 219 fi 220 fi 221 fi 222 223 # Root and uucp should both be in /etc/ftpusers. 224 if [ "$check_ftpusers" = YES ]; then 225 if egrep root /etc/ftpusers > /dev/null ; then 226 : 227 else 228 printf "\nRoot not listed in /etc/ftpusers file.\n" 229 fi 230 if egrep uucp /etc/ftpusers > /dev/null ; then 231 : 232 else 233 printf "\nUucp not listed in /etc/ftpusers file.\n" 234 fi 235 fi 236 237 # Uudecode should not be in the /etc/aliases file. 238 if [ "$check_aliases" = YES ]; then 239 if egrep '^[^#]*(uudecode|decode).*\|' /etc/aliases; then 240 printf "\nEntry for uudecode in /etc/aliases file.\n" 241 fi 242 fi 243 244 # Files that should not have + signs. 245 if [ "$check_rhosts" = YES ]; then 246 list="/etc/hosts.equiv /etc/hosts.lpd" 247 for f in $list ; do 248 if [ -f $f ] && egrep '\+' $f > /dev/null ; then 249 printf "\nPlus sign in $f file.\n" 250 fi 251 done 252 253 # Check for special users with .rhosts files. Only root and toor should 254 # have .rhosts files. Also, .rhosts files should not have plus signs. 255 awk -F: '$1 != "root" && $1 != "toor" && \ 256 ($3 < 100 || $1 == "ftp" || $1 == "uucp") \ 257 { print $1 " " $9 }' $MP | 258 sort -k2 | 259 while read uid homedir; do 260 if [ -f ${homedir}/.rhosts ] ; then 261 rhost=`ls -ldgT ${homedir}/.rhosts` 262 printf "$uid: $rhost\n" 263 fi 264 done > $OUTPUT 265 if [ -s $OUTPUT ] ; then 266 printf "\nChecking for special users with .rhosts files.\n" 267 cat $OUTPUT 268 fi 269 270 awk -F: '{ print $1 " " $9 }' $MP | 271 sort -k2 | 272 while read uid homedir; do 273 if [ -f ${homedir}/.rhosts ] && \ 274 egrep '\+' ${homedir}/.rhosts > /dev/null ; then 275 printf "$uid: + in .rhosts file.\n" 276 fi 277 done > $OUTPUT 278 if [ -s $OUTPUT ] ; then 279 printf "\nChecking .rhosts files syntax.\n" 280 cat $OUTPUT 281 fi 282 fi 283 284 # Check home directories. Directories should not be owned by someone else 285 # or writeable. 286 if [ "$check_homes" = YES ]; then 287 awk -F: '{ print $1 " " $9 }' $MP | 288 sort -k2 | 289 while read uid homedir; do 290 if [ -d ${homedir}/ ] ; then 291 file=`ls -ldgT ${homedir}` 292 printf "$uid $file\n" 293 fi 294 done | 295 awk '$1 != $4 && $4 != "root" \ 296 { print "user " $1 " home directory is owned by " $4 } 297 $2 ~ /^-....w/ \ 298 { print "user " $1 " home directory is group writeable" } 299 $2 ~ /^-.......w/ \ 300 { print "user " $1 " home directory is other writeable" }' > $OUTPUT 301 if [ -s $OUTPUT ] ; then 302 printf "\nChecking home directories.\n" 303 cat $OUTPUT 304 fi 305 306 # Files that should not be owned by someone else or readable. 307 list=".Xauthority .netrc .rhosts" 308 awk -F: '{ print $1 " " $9 }' $MP | 309 sort -k2 | 310 while read uid homedir; do 311 for f in $list ; do 312 file=${homedir}/${f} 313 if [ -f $file ] ; then 314 printf "$uid $f `ls -ldgT $file`\n" 315 fi 316 done 317 done | 318 awk '$1 != $5 && $5 != "root" \ 319 { print "user " $1 " " $2 " file is owned by " $5 } 320 $3 ~ /^-...r/ \ 321 { print "user " $1 " " $2 " file is group readable" } 322 $3 ~ /^-......r/ \ 323 { print "user " $1 " " $2 " file is other readable" } 324 $3 ~ /^-....w/ \ 325 { print "user " $1 " " $2 " file is group writeable" } 326 $3 ~ /^-.......w/ \ 327 { print "user " $1 " " $2 " file is other writeable" }' > $OUTPUT 328 329 # Files that should not be owned by someone else or writeable. 330 list=".bash_history .bash_login .bash_logout .bash_profile .bashrc \ 331 .cshrc .emacs .exrc .forward .history .klogin .login .logout \ 332 .profile .qmail .rc_history .tcshrc .twmrc .xinitrc .xsession" 333 awk -F: '{ print $1 " " $9 }' $MP | 334 sort -k2 | 335 while read uid homedir; do 336 for f in $list ; do 337 file=${homedir}/${f} 338 if [ -f $file ] ; then 339 printf "$uid $f `ls -ldgT $file`\n" 340 fi 341 done 342 done | 343 awk '$1 != $5 && $5 != "root" \ 344 { print "user " $1 " " $2 " file is owned by " $5 } 345 $3 ~ /^-....w/ \ 346 { print "user " $1 " " $2 " file is group writeable" } 347 $3 ~ /^-.......w/ \ 348 { print "user " $1 " " $2 " file is other writeable" }' >> $OUTPUT 349 if [ -s $OUTPUT ] ; then 350 printf "\nChecking dot files.\n" 351 cat $OUTPUT 352 fi 353 fi 354 355 # Mailboxes should be owned by user and unreadable. 356 if [ "$check_varmail" = YES ]; then 357 ls -l /var/mail | sed 1d | \ 358 awk '$3 != $9 \ 359 { print "user " $9 " mailbox is owned by " $3 } 360 $1 != "-rw-------" \ 361 { print "user " $9 " mailbox is " $1 ", group " $4 }' > $OUTPUT 362 if [ -s $OUTPUT ] ; then 363 printf "\nChecking mailbox ownership.\n" 364 cat $OUTPUT 365 fi 366 fi 367 368 if [ "$check_nfs" = YES ]; then 369 if [ -f /etc/exports ]; then 370 # File systems should not be globally exported. 371 awk '{ 372 readonly = 0; 373 for (i = 2; i <= NF; ++i) { 374 if ($i ~ /-ro/) 375 readonly = 1; 376 else if ($i !~ /^-/) 377 next; 378 } 379 if (readonly) 380 print "File system " $1 " globally exported, read-only." 381 else 382 print "File system " $1 " globally exported, read-write." 383 }' < /etc/exports > $OUTPUT 384 if [ -s $OUTPUT ] ; then 385 printf "\nChecking for globally exported file systems.\n" 386 cat $OUTPUT 387 fi 388 fi 389 fi 390 391 # Display any changes in setuid files and devices. 392 if [ "$check_devices" = YES ]; then 393 printf "\nChecking setuid files and devices:\n" 394 (find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \ 395 -o -fstype procfs \) -a -prune -o \ 396 \( \( -perm -u+s -a ! -type d \) -o \ 397 \( -perm -g+s -a ! -type d \) -o \ 398 -type b -o -type c \) -print | \ 399 sort | sed -e 's/^/ls -ldgT /' | sh > $LIST) 2> $OUTPUT 400 401 # Display any errors that occurred during system file walk. 402 if [ -s $OUTPUT ] ; then 403 printf "Setuid/device find errors:\n" 404 cat $OUTPUT 405 printf "\n" 406 fi 407 408 # Display any changes in the setuid file list. 409 egrep -v '^[bc]' $LIST > $TMP1 410 if [ -s $TMP1 ] ; then 411 # Check to make sure uudecode isn't setuid. 412 if grep -w uudecode $TMP1 > /dev/null ; then 413 printf "\nUudecode is setuid.\n" 414 fi 415 416 CUR=/var/backups/setuid.current 417 BACK=/var/backups/setuid.backup 418 419 if [ -s $CUR ] ; then 420 if cmp -s $CUR $TMP1 ; then 421 : 422 else 423 > $TMP2 424 join -110 -210 -v2 $CUR $TMP1 > $OUTPUT 425 if [ -s $OUTPUT ] ; then 426 printf "Setuid additions:\n" 427 tee -a $TMP2 < $OUTPUT 428 printf "\n" 429 fi 430 431 join -110 -210 -v1 $CUR $TMP1 > $OUTPUT 432 if [ -s $OUTPUT ] ; then 433 printf "Setuid deletions:\n" 434 tee -a $TMP2 < $OUTPUT 435 printf "\n" 436 fi 437 438 sort -k10 $TMP2 $CUR $TMP1 | \ 439 sed -e 's/[ ][ ]*/ /g' | uniq -u > $OUTPUT 440 if [ -s $OUTPUT ] ; then 441 printf "Setuid changes:\n" 442 column -t $OUTPUT 443 printf "\n" 444 fi 445 446 cp $CUR $BACK 447 cp $TMP1 $CUR 448 fi 449 else 450 printf "Setuid additions:\n" 451 column -t $TMP1 452 printf "\n" 453 cp $TMP1 $CUR 454 fi 455 fi 456 457 # Check for block and character disk devices that are readable or writeable 458 # or not owned by root.operator. 459 >$TMP1 460 DISKLIST="dk fd hd hk hp jb kra ra rb rd rl rx rz sd up wd xd xy" 461 for i in $DISKLIST; do 462 egrep "^b.*/${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1 463 egrep "^c.*/r${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1 464 done 465 466 awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \ 467 { printf("Disk %s is user %s, group %s, permissions %s.\n", \ 468 $11, $3, $4, $1); }' < $TMP1 > $OUTPUT 469 if [ -s $OUTPUT ] ; then 470 printf "\nChecking disk ownership and permissions.\n" 471 cat $OUTPUT 472 printf "\n" 473 fi 474 475 # Display any changes in the device file list. 476 egrep '^[bc]' $LIST | sort -k11 > $TMP1 477 if [ -s $TMP1 ] ; then 478 CUR=/var/backups/device.current 479 BACK=/var/backups/device.backup 480 481 if [ -s $CUR ] ; then 482 if cmp -s $CUR $TMP1 ; then 483 : 484 else 485 > $TMP2 486 join -111 -211 -v2 $CUR $TMP1 > $OUTPUT 487 if [ -s $OUTPUT ] ; then 488 printf "Device additions:\n" 489 tee -a $TMP2 < $OUTPUT 490 printf "\n" 491 fi 492 493 join -111 -211 -v1 $CUR $TMP1 > $OUTPUT 494 if [ -s $OUTPUT ] ; then 495 printf "Device deletions:\n" 496 tee -a $TMP2 < $OUTPUT 497 printf "\n" 498 fi 499 500 # Report any block device change. Ignore character 501 # devices, only the name is significant. 502 cat $TMP2 $CUR $TMP1 | \ 503 sed -e '/^c/d' | \ 504 sort -k11 | \ 505 sed -e 's/[ ][ ]*/ /g' | \ 506 uniq -u > $OUTPUT 507 if [ -s $OUTPUT ] ; then 508 printf "Block device changes:\n" 509 column -t $OUTPUT 510 printf "\n" 511 fi 512 513 cp $CUR $BACK 514 cp $TMP1 $CUR 515 fi 516 else 517 printf "Device additions:\n" 518 column -t $TMP1 519 printf "\n" 520 cp $TMP1 $CUR 521 fi 522 fi 523 fi 524 525 # Check special files. 526 # Check system binaries. 527 # 528 # Create the mtree tree specifications using: 529 # 530 # mtree -cx -pDIR -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure 531 # chown root.wheel DIR.secure 532 # chmod 600 DIR.secure 533 # 534 # Note, this is not complete protection against Trojan horsed binaries, as 535 # the hacker can modify the tree specification to match the replaced binary. 536 # For details on really protecting yourself against modified binaries, see 537 # the mtree(8) manual page. 538 if [ "$check_mtree" = YES ]; then 539 mtree -e -p / -f /etc/mtree/special > $OUTPUT 540 if [ -s $OUTPUT ]; then 541 printf "\nChecking special files and directories.\n" 542 cat $OUTPUT 543 fi 544 545 > $OUTPUT 546 for file in /etc/mtree/*.secure; do 547 [ $file = '/etc/mtree/*.secure' ] && continue 548 tree=`sed -n -e '3s/.* //p' -e 3q $file` 549 mtree -f $file -p $tree > $TMP1 550 if [ -s $TMP1 ]; then 551 printf "\nChecking $tree:\n" >> $OUTPUT 552 cat $TMP1 >> $OUTPUT 553 fi 554 done 555 if [ -s $OUTPUT ]; then 556 printf "\nChecking system binaries:\n" 557 cat $OUTPUT 558 fi 559 fi 560 561 # List of files that get backed up and checked for any modifications. Each 562 # file is expected to have two backups, /var/backups/file.{current,backup}. 563 # Any changes cause the files to rotate. 564 if [ "$check_changelist" = YES ] && [ -s /etc/changelist ] ; then 565 for file in `cat /etc/changelist`; do 566 CUR=/var/backups/`basename $file`.current 567 BACK=/var/backups/`basename $file`.backup 568 if [ -s $file ]; then 569 if [ -s $CUR ] ; then 570 diff $CUR $file > $OUTPUT 571 if [ -s $OUTPUT ] ; then 572 printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file 573 cat $OUTPUT 574 cp -p $CUR $BACK 575 cp -p $file $CUR 576 chown root.wheel $CUR $BACK 577 fi 578 else 579 cp -p $file $CUR 580 chown root.wheel $CUR 581 fi 582 fi 583 done 584 fi 585
Indexes created Tue Sep 30 07:10:03 GMT 2025