security revision 1.29
1 #!/bin/sh - 2 # 3 # $NetBSD: security,v 1.29 1997/09/23 14:36:56 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 MPBYUID=secure4.$$ 30 MPBYPATH=secure5.$$ 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 > $MPBYUID 40 awk -F: '{ print $1 " " $9 }' $MP | sort -k2 > $MPBYPATH 41 42 # Check the master password file syntax. 43 if [ "$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 < $MPBYUID 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 $MPBYUID 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 > $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 > $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 [ $umaskset = "no" ] ; then 244 printf "\tRoot sh startup files do not set the umask.\n" 245 fi 246 fi 247 fi 248 249 # Root and uucp should both be in /etc/ftpusers. 250 if [ "$check_ftpusers" = YES ]; then 251 > $OUTPUT 252 list="uucp "`awk '$2 == 0 { print $1 }' $MPBYUID` 253 for i in $list; do 254 if /usr/libexec/ftpd -C $i ; then 255 printf "\t$i is not denied\n" >> $OUTPUT 256 fi 257 done 258 if [ -s $OUTPUT ]; then 259 printf "\nChecking the /etc/ftpusers configuration:\n" 260 cat $OUTPUT 261 fi 262 fi 263 264 # Uudecode should not be in the /etc/aliases file. 265 if [ "$check_aliases" = YES ]; then 266 if egrep '^[^#]*(uudecode|decode).*\|' /etc/aliases; then 267 printf "\nEntry for uudecode in /etc/aliases file.\n" 268 fi 269 fi 270 271 # Files that should not have + signs. 272 if [ "$check_rhosts" = YES ]; then 273 list="/etc/hosts.equiv /etc/hosts.lpd" 274 for f in $list ; do 275 if [ -f $f ] && egrep '\+' $f > /dev/null ; then 276 printf "\nPlus sign in $f file.\n" 277 fi 278 done 279 280 # Check for special users with .rhosts files. Only root and toor should 281 # have .rhosts files. Also, .rhosts files should not have plus signs. 282 awk -F: '$1 != "root" && $1 != "toor" && \ 283 ($3 < 100 || $1 == "ftp" || $1 == "uucp") \ 284 { print $1 " " $9 }' $MP | 285 sort -k2 | 286 while read uid homedir; do 287 if [ -f ${homedir}/.rhosts ] ; then 288 rhost=`ls -ldgT ${homedir}/.rhosts` 289 printf "$uid: $rhost\n" 290 fi 291 done > $OUTPUT 292 if [ -s $OUTPUT ] ; then 293 printf "\nChecking for special users with .rhosts files.\n" 294 cat $OUTPUT 295 fi 296 297 while read uid homedir; do 298 if [ -f ${homedir}/.rhosts ] && \ 299 egrep '\+' ${homedir}/.rhosts > /dev/null ; then 300 printf "$uid: + in .rhosts file.\n" 301 fi 302 done < $MPBYPATH > $OUTPUT 303 if [ -s $OUTPUT ] ; then 304 printf "\nChecking .rhosts files syntax.\n" 305 cat $OUTPUT 306 fi 307 fi 308 309 # Check home directories. Directories should not be owned by someone else 310 # or writeable. 311 if [ "$check_homes" = YES ]; then 312 while read uid homedir; do 313 if [ -d ${homedir}/ ] ; then 314 file=`ls -ldgT ${homedir}` 315 printf "$uid $file\n" 316 fi 317 done < $MPBYPATH | 318 awk '$1 != $4 && $4 != "root" \ 319 { print "user " $1 " home directory is owned by " $4 } 320 $2 ~ /^-....w/ \ 321 { print "user " $1 " home directory is group writeable" } 322 $2 ~ /^-.......w/ \ 323 { print "user " $1 " home directory is other writeable" }' \ 324 > $OUTPUT 325 if [ -s $OUTPUT ] ; then 326 printf "\nChecking home directories.\n" 327 cat $OUTPUT 328 fi 329 330 # Files that should not be owned by someone else or readable. 331 list=".Xauthority .netrc" 332 while read uid homedir; do 333 for f in $list ; do 334 file=${homedir}/${f} 335 if [ -f $file ] ; then 336 printf "$uid $f `ls -ldgT $file`\n" 337 fi 338 done 339 done < $MPBYPATH | 340 awk '$1 != $5 && $5 != "root" \ 341 { print "user " $1 " " $2 " file is owned by " $5 } 342 $3 ~ /^-...r/ \ 343 { print "user " $1 " " $2 " file is group readable" } 344 $3 ~ /^-......r/ \ 345 { print "user " $1 " " $2 " file is other readable" } 346 $3 ~ /^-....w/ \ 347 { print "user " $1 " " $2 " file is group writeable" } 348 $3 ~ /^-.......w/ \ 349 { print "user " $1 " " $2 " file is other writeable" }' \ 350 > $OUTPUT 351 352 # Files that should not be owned by someone else or writeable. 353 list=".bash_history .bash_login .bash_logout .bash_profile .bashrc \ 354 .cshrc .emacs .exrc .forward .history .klogin .login .logout \ 355 .profile .qmail .rc_history .rhosts .tcshrc .twmrc .xinitrc \ 356 .xsession" 357 while read uid homedir; do 358 for f in $list ; do 359 file=${homedir}/${f} 360 if [ -f $file ] ; then 361 printf "$uid $f `ls -ldgT $file`\n" 362 fi 363 done 364 done < $MPBYPATH | 365 awk '$1 != $5 && $5 != "root" \ 366 { print "user " $1 " " $2 " file is owned by " $5 } 367 $3 ~ /^-....w/ \ 368 { print "user " $1 " " $2 " file is group writeable" } 369 $3 ~ /^-.......w/ \ 370 { print "user " $1 " " $2 " file is other writeable" }' \ 371 >> $OUTPUT 372 if [ -s $OUTPUT ] ; then 373 printf "\nChecking dot files.\n" 374 cat $OUTPUT 375 fi 376 fi 377 378 # Mailboxes should be owned by user and unreadable. 379 if [ "$check_varmail" = YES ]; then 380 ls -l /var/mail | sed 1d | \ 381 awk '$3 != $9 \ 382 { print "user " $9 " mailbox is owned by " $3 } 383 $1 != "-rw-------" \ 384 { print "user " $9 " mailbox is " $1 ", group " $4 }' > $OUTPUT 385 if [ -s $OUTPUT ] ; then 386 printf "\nChecking mailbox ownership.\n" 387 cat $OUTPUT 388 fi 389 fi 390 391 if [ "$check_nfs" = YES ]; then 392 if [ -f /etc/exports ]; then 393 # File systems should not be globally exported. 394 awk '{ 395 # ignore comments and blank lines 396 if ($LINE ~ /^\#/ || $LINE ~ /^$/ ) 397 next; 398 399 readonly = 0; 400 for (i = 2; i <= NF; ++i) { 401 if ($i ~ /-ro/) 402 readonly = 1; 403 else if ($i !~ /^-/) 404 next; 405 } 406 if (readonly) 407 print "File system " $1 " globally exported, read-only." 408 else 409 print "File system " $1 " globally exported, read-write." 410 }' < /etc/exports > $OUTPUT 411 if [ -s $OUTPUT ] ; then 412 printf "\nChecking for globally exported file systems.\n" 413 cat $OUTPUT 414 fi 415 fi 416 fi 417 418 # Display any changes in setuid files and devices. 419 if [ "$check_devices" = YES ]; then 420 > $ERR 421 (find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \ 422 -o -fstype procfs \) -a -prune -o \ 423 \( \( -perm -u+s -a ! -type d \) -o \ 424 \( -perm -g+s -a ! -type d \) -o \ 425 -type b -o -type c \) -print0 | \ 426 xargs -0 ls -ldgTq | sort +9 > $LIST) 2> $OUTPUT 427 428 # Display any errors that occurred during system file walk. 429 if [ -s $OUTPUT ] ; then 430 printf "Setuid/device find errors:\n" >> $ERR 431 cat $OUTPUT >> $ERR 432 printf "\n" >> $ERR 433 fi 434 435 # Display any changes in the setuid file list. 436 egrep -v '^[bc]' $LIST > $TMP1 437 if [ -s $TMP1 ] ; then 438 # Check to make sure uudecode isn't setuid. 439 if grep -w uudecode $TMP1 > /dev/null ; then 440 printf "\nUudecode is setuid.\n" >> $ERR 441 fi 442 443 CUR=/var/backups/setuid.current 444 BACK=/var/backups/setuid.backup 445 446 if [ -s $CUR ] ; then 447 if cmp -s $CUR $TMP1 ; then 448 : 449 else 450 > $TMP2 451 join -110 -210 -v2 $CUR $TMP1 > $OUTPUT 452 if [ -s $OUTPUT ] ; then 453 printf "Setuid additions:\n" >> $ERR 454 tee -a $TMP2 < $OUTPUT >> $ERR 455 printf "\n" >> $ERR 456 fi 457 458 join -110 -210 -v1 $CUR $TMP1 > $OUTPUT 459 if [ -s $OUTPUT ] ; then 460 printf "Setuid deletions:\n" >> $ERR 461 tee -a $TMP2 < $OUTPUT >> $ERR 462 printf "\n" >> $ERR 463 fi 464 465 sort -k10 $TMP2 $CUR $TMP1 | \ 466 sed -e 's/[ ][ ]*/ /g' | \ 467 uniq -u > $OUTPUT 468 if [ -s $OUTPUT ] ; then 469 printf "Setuid changes:\n" >> $ERR 470 column -t $OUTPUT >> $ERR 471 printf "\n" >> $ERR 472 fi 473 474 cp $CUR $BACK 475 cp $TMP1 $CUR 476 fi 477 else 478 printf "Setuid additions:\n" >> $ERR 479 column -t $TMP1 >> $ERR 480 printf "\n" >> $ERR 481 cp $TMP1 $CUR 482 fi 483 fi 484 485 # Check for block and character disk devices that are readable or 486 # writeable or not owned by root.operator. 487 >$TMP1 488 DISKLIST="acd ccd cd ch fd hk hp mcd md ra rb rd rl rx rz \ 489 sd se ss tz uk up vnd wd xd xy" 490 # DISKLIST="$DISKLIST ct mt st wt" 491 for i in $DISKLIST; do 492 egrep "^b.*/${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1 493 egrep "^c.*/r${i}[0-9][0-9]*[a-p]$" $LIST >> $TMP1 494 done 495 496 awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \ 497 { printf "Disk %s is user %s, group %s, permissions %s.\n", \ 498 $11, $3, $4, $1; }' < $TMP1 > $OUTPUT 499 if [ -s $OUTPUT ] ; then 500 printf "\nChecking disk ownership and permissions.\n" >> $ERR 501 cat $OUTPUT >> $ERR 502 printf "\n" >> $ERR 503 fi 504 505 # Display any changes in the device file list. 506 egrep '^[bc]' $LIST | sort -k11 > $TMP1 507 if [ -s $TMP1 ] ; then 508 CUR=/var/backups/device.current 509 BACK=/var/backups/device.backup 510 511 if [ -s $CUR ] ; then 512 if cmp -s $CUR $TMP1 ; then 513 : 514 else 515 > $TMP2 516 join -111 -211 -v2 $CUR $TMP1 > $OUTPUT 517 if [ -s $OUTPUT ] ; then 518 printf "Device additions:\n" >> $ERR 519 tee -a $TMP2 < $OUTPUT >> $ERR 520 printf "\n" >> $ERR 521 fi 522 523 join -111 -211 -v1 $CUR $TMP1 > $OUTPUT 524 if [ -s $OUTPUT ] ; then 525 printf "Device deletions:\n" >> $ERR 526 tee -a $TMP2 < $OUTPUT >> $ERR 527 printf "\n" >> $ERR 528 fi 529 530 # Report any block device change. Ignore 531 # character devices, only the name is 532 # significant. 533 cat $TMP2 $CUR $TMP1 | \ 534 sed -e '/^c/d' | \ 535 sort -k11 | \ 536 sed -e 's/[ ][ ]*/ /g' | \ 537 uniq -u > $OUTPUT 538 if [ -s $OUTPUT ] ; then 539 printf "Block device changes:\n" >> $ERR 540 column -t $OUTPUT >> $ERR 541 printf "\n" >> $ERR 542 fi 543 544 cp $CUR $BACK 545 cp $TMP1 $CUR 546 fi 547 else 548 printf "Device additions:\n" >> $ERR 549 column -t $TMP1 >> $ERR 550 printf "\n" >> $ERR 551 cp $TMP1 $CUR >> $ERR 552 fi 553 fi 554 if [ -s $ERR ] ; then 555 printf "\nChecking setuid files and devices:\n" 556 cat $ERR 557 printf "\n" 558 fi 559 fi 560 561 # Check special files. 562 # Check system binaries. 563 # 564 # Create the mtree tree specifications using: 565 # 566 # mtree -cx -pDIR -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure 567 # chown root.wheel DIR.secure 568 # chmod 600 DIR.secure 569 # 570 # Note, this is not complete protection against Trojan horsed binaries, as 571 # the hacker can modify the tree specification to match the replaced binary. 572 # For details on really protecting yourself against modified binaries, see 573 # the mtree(8) manual page. 574 if [ "$check_mtree" = YES ]; then 575 mtree -e -p / -f /etc/mtree/special > $OUTPUT 576 if [ -s $OUTPUT ]; then 577 printf "\nChecking special files and directories.\n" 578 cat $OUTPUT 579 fi 580 581 > $OUTPUT 582 for file in /etc/mtree/*.secure; do 583 [ $file = '/etc/mtree/*.secure' ] && continue 584 tree=`sed -n -e '3s/.* //p' -e 3q $file` 585 mtree -f $file -p $tree > $TMP1 586 if [ -s $TMP1 ]; then 587 printf "\nChecking $tree:\n" >> $OUTPUT 588 cat $TMP1 >> $OUTPUT 589 fi 590 done 591 if [ -s $OUTPUT ]; then 592 printf "\nChecking system binaries:\n" 593 cat $OUTPUT 594 fi 595 fi 596 597 # List of files that get backed up and checked for any modifications. Each 598 # file is expected to have two backups, /var/backups/file.{current,backup}. 599 # Any changes cause the files to rotate. 600 if [ "$check_changelist" = YES ] && [ -s /etc/changelist ] ; then 601 for file in `egrep -v "^#|$MP" /etc/changelist`; do 602 CUR=/var/backups/`basename $file`.current 603 BACK=/var/backups/`basename $file`.backup 604 if [ -s $file ]; then 605 if [ -s $CUR ] ; then 606 diff $CUR $file > $OUTPUT 607 if [ -s $OUTPUT ] ; then 608 printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file 609 cat $OUTPUT 610 cp -p $CUR $BACK 611 cp -p $file $CUR 612 chown root.wheel $CUR $BACK 613 fi 614 else 615 cp -p $file $CUR 616 chown root.wheel $CUR 617 fi 618 fi 619 done 620 fi 621
Indexes created Mon Sep 29 21:09:56 GMT 2025