1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
|
---
policy: 'ANSSI-BP-028'
title: 'Configuration Recommendations of a GNU/Linux System'
id: anssi
version: '2.0'
source: https://cyber.gouv.fr/sites/default/files/document/linux_configuration-en-v2.pdf
levels:
- id: minimal
- id: intermediary
inherits_from:
- minimal
- id: enhanced
inherits_from:
- intermediary
- id: high
inherits_from:
- enhanced
reference_type: anssi
controls:
- id: R1
title: Hardware Support
levels:
- enhanced
description: >-
It is recommended to apply the configuration recommendations for Hardware support
mentioned in ANSSI DAT-24.
notes: >-
This requirement can be checked, but remediation requires manual reinstall of the OS.
The content automation cannot really configure the BIOS, but can in some cases,
check settings that are visible to the OS. Like for example the NX/DX setting.
status: automated
rules:
# From ANSSI DAT-24
# R1 and R2 Prefer 64 bit OS
- prefer_64bit_os
# R3 If using 32 bit OS, PAE mode should be enabled
- install_PAE_kernel_on_x86-32
# R5 It is recommended to use hardware and OS that support SMEP
- grub2_nosmep_argument_absent
# R6 It is recommended to use hardware and OS that support SMAP
- grub2_nosmap_argument_absent
# R7 It is recommended to use hardware and OS that support AES-NI
- package_dracut-fips-aesni_installed
# R8 It is recommended to use hardware with support for hardware random number generator
# R9 Disable VT-x AMD-V technologies
# TODO: can we reliably check cpuinfo flags?
# R10 IOMMU must enabled if the hardware supports it
- id: R2
title: Hardware configuration
levels:
- intermediary
description: >-
It is recommended to apply the configuration recommendations for BIOS/UEFI mentioned in
ANSSI DAT-24.
notes: >-
Configurations recommended for this requirement are to be performed at the BIOS level.
status: manual
# From ANSSI DAT-24
# R11 Password protect the BIOS
# R12 Deactivate peripherals not needed
# R13 The boot order list should give highest preference to component on which final OS is installed
# R14 Enable NX/XD bit
# - bios_enable_execution_restrictions # Doesn't have check
# R15 Disable VT-x/AMD-V functionality
# R16 Enable IOMMU
- id: R3
title: UEFI Secure boot activation
levels:
- intermediary
description: >-
It is recommended to apply UEFI Secure Boot configuration of the distribution.
notes: >-
Secure Boot needs to be enabled in the UEFI Setup program.
Enabling Secure Boot can't be accomplished from the operating system.
Also, OVAL doesn't provide any reliable ways to detect the Secure Boot status.
Therefore, we will not provide any rules to automate this requirement.
We recommend checking the Secure Boot status using the `mokutil --sb-state` or `bootctl status`
commands.
status: manual
- id: R4
title: Replacing of preloaded keys
levels:
- high
description: >-
It is recommended to replace the UEFI preloaded keys with new keys used to sign;
the bootloader and Linux kernel, or; the image of the Linux kernel in EFI format.
notes: >-
This requirement is not generally automatable. The Machine Owner Key (MOK) could
be used to add keys to the Secure Boot db key database but manual interaction is
required to navigate the UEFI console and input the key password.
On systems where MOK utility is not supported, one will need to access the UEFI
firmware interface to add new keys.
We have no automation support for UEFI interfaces and the steps for each hardware
manufacturer can vary.
status: manual
- id: R5
title: Boot loader password
levels:
- intermediary
description: >-
A password protecting the boot loader must exist.
This password must prevent any user from changing their configuration options.
status: automated
rules:
- grub2_password
- grub2_uefi_password
- id: R6
title: Protecting kernel command line parameters
levels:
- high
description: >-
It is recommended that UEFI Secure Boot is used to protect the Linux Kernel
command line parameters during boot.
notes: >-
To protect the Linux Kernel command line one needs to create an Unified Kernel Image and use
it with the UEFI Secure Boot mechanism.
To check if the Kernel image contains the kernel command one needs to inspect the binary, on
the command line one can use the objdump command. But unfortunately OVAL is not able to
inspect kernel images.
Also, it is not trivial to automate creation of such image or configuration of the
Secure Boot mechanism.
status: manual
- id: R7
title: IOMMU Configuration Guidelines
levels:
- enhanced
description: >-
The iommu = force directive must be added to the list of kernel parameters
during startup in addition to those already present in the configuration
files of the bootloader (/boot/grub/menu.lst or /etc/default/grub).
status: automated
rules:
- grub2_enable_iommu_force
- id: R8
title: Memory configuration options
levels:
- intermediary
status: automated
rules:
# l1tf=full,force to enable countermeasure for L1 Terminal Fault vulnerability, or
# l1tf=off to maximize performance, when system is not a hypervisor or VMs are trusted
- grub2_l1tf_argument
- var_l1tf_options=full_force
# page_poison=on: activate the poisoning of the pages of the page allocator (buddy allocator)
- grub2_page_poison_argument
# pti=on: force the use of Page Table Isolation (PTI) including on processors claiming
# not to be affected by the Meltdown vulnerability;
- grub2_pti_argument
# slab_nomerge=yes (equivalent to CONFIG_SLAB_MERGE_DEFAULT=n): disables the merging of
# slab caches (dynamic memory allocations) of identical size.
- grub2_slab_nomerge_argument
# slub_debug=F,Z,P: activate certain options for checking slabs caches (dynamic memory allocation)
- grub2_slub_debug_argument
- var_slub_debug_options=FZP
# spec_store_bypass_disable=seccomp: force the system to use the default countermeasure
# (on an x86 system supporting seccomp) for the Specter v4 (Speculative Store Bypass) vulnerability
- grub2_spec_store_bypass_disable_argument
- var_spec_store_bypass_disable_options=seccomp
# spectre_v2=on: force the system to use a countermeasure for the Specter v2 (Branch Target Injection) vulnerability.
- grub2_spectre_v2_argument
# mds=full,nosmt: force the system to use Microarchitectural Data Sampling (MDS) to
# mitigate the vulnerabilities of Intel processors.
- grub2_mds_argument
- var_mds_options=full_nosmt
# mce=0: force a kernel panic on uncorrected errors reported by Machine Check support.
- grub2_mce_argument
# page_alloc.shuffle=1: enables Page allocator randomization
- grub2_page_alloc_shuffle_argument
# rng_core.default_quality=500: increase confidence in TPM's HWRNG for robust and fast
# Linux CSPRNG initialization by crediting half of the entropy it provides.
- grub2_rng_core_default_quality_argument
- var_rng_core_default_quality=500
# Forbidden to map memory in low addresses (0)
# vm.mmap_min_addr = 65536
- sysctl_vm_mmap_min_addr
- id: R9
title: Kernel configuration options
levels:
- intermediary
status: automated
rules:
# Restrict access to the dmesg buffer (equivalent to
# CONFIG_SECURITY_DMESG_RESTRICT=y)
- sysctl_kernel_dmesg_restrict
# Hide kernel addresses in /proc and various other interfaces,
# including from privileged users
- sysctl_kernel_kptr_restrict
- sysctl_kernel_kptr_restrict_value=2
# Explicitly specify the process id space supported by the kernel,
# 65536 being an example value
# kernel.pid_max=65536
- sysctl_kernel_pid_max
# Restricts the use of the perf system
# kernel.perf_event_max_sample_rate = 1
# kernel.perf_cpu_time_max_percent = 1
- sysctl_kernel_perf_event_max_sample_rate
- sysctl_kernel_perf_cpu_time_max_percent
# Prohibit unprivileged access to the perf_event_open () system call.
# With a value greater than 2, we impose the possession of
# CAP_SYS_ADMIN, in order to collect the perf events.
# kernel.perf_event_paranoid = 2
- sysctl_kernel_perf_event_paranoid
# Activate ASLR
- sysctl_kernel_randomize_va_space
# Disable Magic System Request Key combinations
# kernel.sysrq = 0
- sysctl_kernel_sysrq
# Restrict kernel BPF usage to privileged users
# kernel.unprivileged_bpf_disabled=1
- sysctl_kernel_unprivileged_bpf_disabled
# Completely shut down the system if the Linux kernel behaves
# unexpectedly kernel.panic_on_oops=1
- sysctl_kernel_panic_on_oops
- id: R10
title: Disabling the loading of kernel modules
levels:
- enhanced
description: >-
The loading of the kernel modules can be blocked by the activation of the
sysctl kernel.modules_disabled:
Prohibition of loading modules (except those already loaded to this point)
kernel.modules_disabled = 1
status: automated
rules:
- sysctl_kernel_modules_disabled
- id: R11
title: Yama module sysctl configuration
levels:
- intermediary
description: >-
It is recommended to load the Yama security module at startup (by example
passing the security = yama argument to the kernel) and configure the
sysctl kernel.yama.ptrace_scope to a value of at least 1.
status: automated
rules:
- sysctl_kernel_yama_ptrace_scope
- id: R12
title: IPv4 configuration options
levels:
- intermediary
status: automated
rules:
# Mitigation of the dispersion effect of the kernel JIT at the cost of a
# compromise on the associated performance.
# net.core.bpf_jit_harden=2
- sysctl_net_core_bpf_jit_harden
# No routing between interfaces
# net.ipv4.ip_forward = 0
- sysctl_net_ipv4_ip_forward
# Consider as invalid the packets received from outside whose source
# is the 127/8 network.
# net.ipv4.conf.all.accept_local=0
- sysctl_net_ipv4_conf_all_accept_local
# Deny receipt of ICMP redirect packets
# net.ipv4.conf.all.accept_redirects = 0
- sysctl_net_ipv4_conf_all_accept_redirects_value=disabled
- sysctl_net_ipv4_conf_all_accept_redirects
# net.ipv4.conf.default.accept_redirects = 0
- sysctl_net_ipv4_conf_default_accept_redirects_value=disabled
- sysctl_net_ipv4_conf_default_accept_redirects
# net.ipv4.conf.all.secure_redirects = 0
- sysctl_net_ipv4_conf_all_secure_redirects
# net.ipv4.conf.default.secure_redirects = 0
- sysctl_net_ipv4_conf_default_secure_redirects
# net.ipv4.conf.all.shared_media=0
- sysctl_net_ipv4_conf_all_shared_media
- sysctl_net_ipv4_conf_all_shared_media_value=disabled
- sysctl_net_ipv4_conf_default_shared_media
- sysctl_net_ipv4_conf_default_shared_media_value=disabled
# Deny the source routing header information supplied by the
# packet to determine its route.
# net.ipv4.conf.all.accept_source_route = 0
- sysctl_net_ipv4_conf_all_accept_source_route
# net.ipv4.conf.default.accept_source_route = 0
- sysctl_net_ipv4_conf_default_accept_source_route
# Prevent the Linux kernel from handling the ARP table globally.
- sysctl_net_ipv4_conf_all_arp_filter
# Respond to ARP requests only if the source and destination address are on the
# same network and come from the same interface on which the packet was received.
# Note that the configuration of this option is to be studied according to the
# use case.
- sysctl_net_ipv4_conf_all_arp_ignore
- sysctl_net_ipv4_conf_all_arp_ignore_value=2
# Refuse the routing of packets whose source or destination address is that
# of the local loopback.
# net.ipv4.conf.all.route_localnet=0
- sysctl_net_ipv4_conf_all_route_localnet
# Ignore gratuitous ARP requests.
# net.ipv4.conf.all.drop_gratuitous_arp=1
- sysctl_net_ipv4_conf_all_drop_gratuitous_arp
# Check that the source address of packets received on a given interface
# would have been contacted via this same interface.
# net.ipv4.conf.all.rp_filter = 1
- sysctl_net_ipv4_conf_all_rp_filter
# net.ipv4.conf.default.rp_filter = 1
- sysctl_net_ipv4_conf_default_rp_filter
# A non-routing equipment has no reason to receive a flow for which it is not the
# recipient and therefore to send an ICMP redirect packet.
# net.ipv4.conf.all.send_redirects = 0
- sysctl_net_ipv4_conf_all_send_redirects
# net.ipv4.conf.default.send_redirects = 0
- sysctl_net_ipv4_conf_default_send_redirects
# Ignore responses that do not comply with RFC 1122
# net.ipv4.icmp_ignore_bogus_error_responses = 1
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
# Increase the range for ephemeral ports
# net.ipv4.ip_local_port_range = 32768 65535
- sysctl_net_ipv4_ip_local_port_range
# RFC 1337
# net.ipv4.tcp_rfc1337 = 1
- sysctl_net_ipv4_tcp_rfc1337
# Use SYN cookies
# net.ipv4.tcp_syncookies = 1
- sysctl_net_ipv4_tcp_syncookies
- id: R13
title: Disabling IPv6
levels:
- intermediary
notes: >-
When IPv6 is not in use, disable it, otherwise secure the IPv6 stack.
This control hardens the IPv6 stack, to disable it use the related rules instead.
status: automated
rules:
# Disable support for "router solicitations"
# net.ipv6.conf.all.router_solicitations = 0
# net.ipv6.conf.default.router_solicitations = 0
- sysctl_net_ipv6_conf_all_router_solicitations
- sysctl_net_ipv6_conf_default_router_solicitations
# Do not accept "router preferences" by "router advertisements"
# net.ipv6.conf.all.accept_ra_rtr_pref = 0
# net.ipv6.conf.default.accept_ra_rtr_pref = 0
- sysctl_net_ipv6_conf_all_accept_ra_rtr_pref
- sysctl_net_ipv6_conf_default_accept_ra_rtr_pref
# No auto configuration of prefixes by router advertisements
# net.ipv6.conf.all.accept_ra_pinfo = 0
# net.ipv6.conf.default.accept_ra_pinfo = 0
- sysctl_net_ipv6_conf_all_accept_ra_pinfo
- sysctl_net_ipv6_conf_default_accept_ra_pinfo
# No default router learning by router advertisements
# net.ipv6.conf.all.accept_ra_defrtr = 0
# net.ipv6.conf.default.accept_ra_defrtr = 0
- sysctl_net_ipv6_conf_all_accept_ra_defrtr
- sysctl_net_ipv6_conf_default_accept_ra_defrtr
# No auto configuration of addresses from "routers" advertisements
# net.ipv6.conf.all.autoconf = 0
# net.ipv6.conf.default.autoconf = 0
- sysctl_net_ipv6_conf_all_autoconf
- sysctl_net_ipv6_conf_default_autoconf
# Do not accept ICMPs of redirect type
# net.ipv6.conf.all_accept_redirects = 0
- sysctl_net_ipv6_conf_all_accept_redirects
# net.ipv6.conf.default.accept_redirects = 0
- sysctl_net_ipv6_conf_default_accept_redirects
# Deny routing source packets
# net.ipv6.conf.all.accept_source_route = 0
- sysctl_net_ipv6_conf_all_accept_source_route
# net.ipv6.conf.default.accept_source_route = 0
- sysctl_net_ipv6_conf_default_accept_source_route
# Maximum number of autoconfigured addresses per interface
# net.ipv6.conf.all.max_addresses = 1
# net.ipv6.conf.default.max_addresses = 1
- sysctl_net_ipv6_conf_all_max_addresses
- sysctl_net_ipv6_conf_default_max_addresses
related_rules:
# Rules to select when disabling the IPv6 stack.
- sysctl_net_ipv6_conf_all_disable_ipv6
- sysctl_net_ipv6_conf_default_disable_ipv6
- id: R14
title: File system configuration options
levels:
- intermediary
notes: >-
The rule for the /proc file system is not implemented
status: automated
rules:
# Disable coredump creation for setuid executables
- sysctl_fs_suid_dumpable
# Available from version 4.19 of the Linux kernel, allows to prohibit
# opening FIFOs and "regular" files that are not owned by the user
# in sticky folders for everyone to write.
# fs.protected_fifos=2
- sysctl_fs_protected_fifos
# fs.protected_regular=2
- sysctl_fs_protected_regular
# Restrict the creation of symbolic links to files that the user owns.
- sysctl_fs_protected_symlinks
# Restrict the creation of hard links to files whose user is owner.
- sysctl_fs_protected_hardlinks
- id: R15
title: Compile options for memory management
levels:
- high
status: automated
notes: >-
The special case of direct access to physical memory is not handled.
rules:
- kernel_config_strict_kernel_rwx
- kernel_config_debug_wx
- kernel_config_debug_fs
- kernel_config_stackprotector
- kernel_config_stackprotector_strong
- kernel_config_sched_stack_end_check
- kernel_config_hardened_usercopy
- kernel_config_hardened_usercopy_fallback
- kernel_config_vmap_stack
- kernel_config_refcount_full
- kernel_config_fortify_source
- kernel_config_acpi_custom_method
- kernel_config_devkmem
- kernel_config_proc_kcore
- kernel_config_compat_vdso
- kernel_config_security_dmesg_restrict
- kernel_config_retpoline
- kernel_config_legacy_vsyscall_none
- kernel_config_legacy_vsyscall_emulate
- kernel_config_legacy_vsyscall_xonly
- kernel_config_x86_vsyscall_emulation
- id: R16
title: Compile options for kernel data structures
levels:
- high
status: automated
rules:
- kernel_config_debug_credentials
- kernel_config_debug_notifiers
- kernel_config_debug_list
- kernel_config_debug_sg
- kernel_config_bug_on_data_corruption
- id: R17
title: Compile options for the memory allocator
levels:
- high
status: automated
rules:
- kernel_config_slab_freelist_random
- kernel_config_slab_freelist_hardened
- kernel_config_slab_merge_default
- kernel_config_slub_debug
- kernel_config_page_poisoning
- kernel_config_page_poisoning_no_sanity
- kernel_config_page_poisoning_zero
- kernel_config_compat_brk
- id: R18
title: Compile options for the management of kernel module
levels:
- high
status: automated
rules:
- kernel_config_strict_module_rwx
- kernel_config_module_sig
- kernel_config_module_sig_force
- kernel_config_module_sig_all
- kernel_config_module_sig_sha512
- kernel_config_module_sig_hash
- kernel_config_module_sig_key
- id: R19
title: Compile options for abnormal situations
levels:
- high
status: automated
rules:
- kernel_config_bug
- kernel_config_panic_on_oops
- kernel_config_panic_timeout
- id: R20
title: Compile options for kernel security functions
levels:
- high
status: automated
rules:
- kernel_config_seccomp
- kernel_config_seccomp_filter
- kernel_config_security
- kernel_config_security_yama
- kernel_config_security_writable_hooks
- id: R21
title: Compile options for the compiler plugins
levels:
- high
status: automated
rules:
- kernel_config_gcc_plugin_latent_entropy
- kernel_config_gcc_plugin_stackleak
- kernel_config_gcc_plugin_structleak
- kernel_config_gcc_plugin_structleak_byref_all
- kernel_config_gcc_plugin_randstruct
- id: R22
title: Compile options for the IP stack
levels:
- high
notes: >-
This control doesn't disable the IPv6 stack, to disable it select the related rule.
status: automated
rules:
- kernel_config_syn_cookies
related_rules:
- kernel_config_ipv6
- id: R23
title: Compile options for various kernel behaviors
levels:
- high
notes: >-
If the system can function without support for kernel modules, module support should be disabled
by setting CONFIG_MODULES=n.
status: automated
rules:
- kernel_config_kexec
- kernel_config_hibernation
- kernel_config_binfmt_misc
- kernel_config_legacy_ptys
- id: R24
title: Compile options for 32-bit architectures
levels:
- high
notes: >-
Unless a X86 32bit kernel is explicitly supported by one of products in the project, this
requirement is set to not applicable.
status: not applicable
- id: R25
title: Compile options for x86_64 architectures
levels:
- high
status: automated
rules:
# TODO: add support for variable for config_default_mmap_min_addr
# CONFIG_DEFAULT_MMAP_MIN_ADDR=65536
- kernel_config_default_mmap_min_addr
- kernel_config_randomize_base
- kernel_config_randomize_memory
- kernel_config_page_table_isolation
- kernel_config_ia32_emulation
- kernel_config_modify_ldt_syscall
- id: R26
title: Compile options for ARM architectures
levels:
- high
notes: >-
Unless a ARM 32bit kernel is explicitly supported by one of products in the project, this
requirement is set to not applicable.
status: not applicable
- id: R27
title: Compile options for ARM 64 architectures
levels:
- high
status: automated
rules:
# CONFIG_DEFAULT_MMAP_MIN_ADDR=32768
- kernel_config_default_mmap_min_addr
- kernel_config_randomize_base
- kernel_config_arm64_sw_ttbr0_pan
- kernel_config_unmap_kernel_at_el0
- id: R28
title: Partitioning type
levels:
- intermediary
status: automated
rules:
# this covers nodev options
- mount_option_nodev_nonroot_local_partitions
# The recommended partitioning type is as follows:
# / <without option> Root partition, contains the rest of the tree
# /boot nosuid, nodev, noexec (optional noauto) Contains the kernel and the bootloader.
# No access required once the boot finished (except update)
- partition_for_boot
- mount_option_boot_nosuid
- mount_option_boot_noexec
# The noauto option rule breaks checking of the other mount options
# Commented until rules for /boot mount_option handles this use case
# - mount_option_boot_noauto
# /opt nosuid, nodev (optional ro) Additional packages to the system.
# Read-only editing if not used
- partition_for_opt
- mount_option_opt_nosuid
# /tmp nosuid, noexec temporary files. Must contain only non-executable elements.
# Cleaned after reboot. Prefferred tmpfs.
- systemd_tmp_mount_enabled
- mount_option_tmp_nosuid
- mount_option_tmp_noexec
# /srv nosuid, nodev (noexec, optional ro) Contains files served by a service type web, ftp, etc
- partition_for_srv
- mount_option_srv_nosuid
# /home nosuid, nodev, noexec Contains the HOME users. Read-only editing if not in use
- partition_for_home
- mount_option_home_nosuid
- mount_option_home_noexec
# /usr nodev Contains the majority of utilities and system files
- partition_for_usr
# /var nosuid, nodev, noexec Partition containing variable files during the life of the system (mails, PID files, databases of a service)
- partition_for_var
- mount_option_var_nosuid
- mount_option_var_noexec
# /var/log nosuid, nodev, noexec Contains system logs
- partition_for_var_log
- mount_option_var_log_noexec
- mount_option_var_log_nosuid
# /var/tmp nosuid, nodev, noexec Temporary files kept after extinction
- partition_for_var_tmp
- mount_option_var_tmp_nosuid
- mount_option_var_tmp_noexec
related_rules:
# /proc hidepid = 2 Contains process information and the system
- mount_option_proc_hidepid
- id: R29
title: Access Restrictions on /boot
levels:
- enhanced
description: >-
When possible, it is recommended not to automatically mount the /boot partition.
In any case, access to the /boot folder should only be allowed for the root user.
notes: >-
The /boot partition mounted is essential to perform certain administrative actions, for
example updating the kernel. Therefore, for better stability, in this requirement only rules
to restrict the access to /boot are selected. It is not changed how the /boot is mounted.
status: automated
rules:
- file_groupowner_efi_grub2_cfg
- file_groupowner_grub2_cfg
- file_owner_efi_grub2_cfg
- file_owner_grub2_cfg
- file_permissions_efi_grub2_cfg
- file_permissions_grub2_cfg
- file_groupowner_efi_user_cfg
- file_groupowner_user_cfg
- file_owner_efi_user_cfg
- file_owner_user_cfg
- file_permissions_efi_user_cfg
- file_permissions_user_cfg
- file_groupowner_systemmap
- file_owner_systemmap
- file_permissions_systemmap
related_rules:
- mount_option_boot_noauto
- id: R30
title: Removal of unused user accounts
levels:
- minimal
description: >-
Unused user accounts must be deleted from the system.
notes: >-
The definition of unused user accounts is broad. It can include accounts
whose owners don't use the system anymore, or users created by services
or applications that should not be used.
Automation by itself cannot discern which accounts are used or not.
status: manual
- id: R31
title: User password strength
levels:
- minimal
notes: >-
The rules selected below establish a general password strength baseline
of 100 bits, based on the recommendations of the technical note
"Recommandations relatives à l'authentification multifacteur et aux mots de passe"
(https://cyber.gouv.fr/publications/recommandations-relatives-lauthentification-multifacteur-et-aux-mots-de-passe)
The baseline should be reviewed and tailored to the system's use case and needs.
status: automated
rules:
# enable authselect to support following rules
- enable_authselect
# Set the maximum password age for the root account to 1 year
- var_accounts_maximum_age_root=365
- accounts_password_set_max_life_root
# Ensure passwords with minimum of 15 characters
- var_password_pam_minlen=15
- accounts_password_pam_minlen
- cracklib_accounts_password_pam_minlen
# Enforce password lenght for new accounts
- var_accounts_password_minlen_login_defs=15
- accounts_password_minlen_login_defs
# Require at Least 1 Special Character in Password
- var_password_pam_ocredit=1
- accounts_password_pam_ocredit
- cracklib_accounts_password_pam_ocredit
# Require at Least 1 Numeric Character in Password
- var_password_pam_dcredit=1
- cracklib_accounts_password_pam_dcredit
- accounts_password_pam_dcredit
# Require at Least 1 Uppercase Character in Password
- var_password_pam_ucredit=1
- accounts_password_pam_ucredit
- cracklib_accounts_password_pam_ucredit
# Require at Least 1 Lowercase Character in Password
- var_password_pam_lcredit=1
- cracklib_accounts_password_pam_lcredit
- accounts_password_pam_lcredit
# Lock out users after 3 failed authentication attempts within 15 min
- var_accounts_passwords_pam_faillock_fail_interval=900
- accounts_passwords_pam_faillock_interval
- var_accounts_passwords_pam_faillock_deny=3
- accounts_passwords_pam_faillock_deny
- accounts_passwords_pam_faillock_deny_root
# same as above but for pam_tally2 module
- accounts_passwords_pam_tally2_deny_root
- var_password_pam_tally2=5
- accounts_passwords_pam_tally2
- accounts_passwords_pam_tally2_unlock_time
- var_accounts_passwords_pam_tally2_unlock_time=1800
# Automatically unlock users after 15 min to prevent DoS
- var_accounts_passwords_pam_faillock_unlock_time=900
- accounts_passwords_pam_faillock_unlock_time
# Do not reuse last two passwords
- var_password_pam_unix_remember=2
- accounts_password_pam_unix_remember
- id: R32
title: Configuring a timeout on local user sessions
levels:
- intermediary
description: >-
Local user sessions (console TTY, graphical session) must be locked after a certain period
of inactivity.
notes: >-
ANSSI doesn't specify the length of the inactivity period, we are choosing 10 minutes as reasonable
number.
status: automated
rules:
- logind_session_timeout
- var_logind_session_timeout=10_minutes
- accounts_tmout
- var_accounts_tmout=10_min
- id: R33
title: Use of dedicated administration accounts
levels:
- intermediary
notes: >-
By disabling direct root logins proper accountability is ensured.
Users will login first, then escalate to privileged (root) access.
Change of privilege operations must be based on executables to monitor the activities
performed (for example sudo).
Nonetheless, the content automation cannot ensure that each administrator was given a
nominative administration account separate from his normal user account.
status: automated
rules:
- no_direct_root_logins
- sshd_disable_root_login
- package_sudo_installed
- audit_rules_privileged_commands_sudo
- service_auditd_enabled
- package_audit_installed
- id: R34
title: Deactivation of service accounts
levels:
- intermediary
notes: >-
It is difficult to generally identify the system's service accounts.
UIDs of such accounts are generally between SYS_UID_MIN and SYS_UID_MAX, but their values
are not enforced by the OS and can be changed over time.
Assisting rules could list users which are not disabled for manual review.
status: manual
- id: R35
title: Uniqueness and exclusivity of system service accounts
levels:
- intermediary
description: >-
Each service must have its own system account and be dedicated to it exclusively.
notes: >-
It is not trivial to identify whether a user account is a service account.
UIDs of such accounts are generally between SYS_UID_MIN and SYS_UID_MAX, but their values
are not enforced by the OS and can be changed over time.
status: manual
- id: R36
title: Changing the default value of UMASK
levels:
- enhanced
description: >-
The default value of UMASK for the shells must be set to 0077 in order to allow read and
write access to its owner only. This value can be defined in the configuration file
/etc/profile that most shells (bash, dash, ksh…) will use.
The default value of UMASK for services must be determined for each service, but in most
cases, it should be set to 0027 (or more restrictive). This allows read access to its owner
and its group, and a full access to its owner. For services such as systemd, this value can
be defined directly in the configuration file of the service with the directive UMask=0027.
notes: >-
There are cases of Systemd services which would stop working in case umask
would be configured to 0027 for all services. One such example is the
Cups service which needs to create sockets which need to be available for
all users. Therefore, this part of the requirement can't be automated.
status: automated
rules:
- accounts_umask_etc_bashrc
- accounts_umask_etc_login_defs
- accounts_umask_etc_profile
- var_accounts_user_umask=077
- id: R37
title: Using access control features
levels:
- enhanced
description: >-
It is recommended to use the mandatory access control (MAC) features in
addition to the traditional Unix user model (DAC), or possibly combine
them with partitioning mechanisms.
notes: >-
Other partitioning mechanisms can include chroot and containers and are not contemplated
in this requirement.
status: automated
rules:
- selinux_state
- var_selinux_state=enforcing
- id: R38
title: Group dedicated to the use of sudo
levels:
- enhanced
description: >-
A group dedicated to the use of sudo must be created, and only members of this
group are allowed to execute sudo.
status: automated
rules:
- sudo_dedicated_group
- var_sudo_dedicated_group=sudogrp
- file_permissions_sudo
- id: R39
title: Sudo configuration guidelines
levels:
- intermediary
status: automated
rules:
- sudo_add_noexec
- sudo_add_requiretty
- sudo_add_use_pty
- sudo_add_umask
- var_sudo_umask=0077
- sudo_add_ignore_dot
- sudo_add_env_reset
- id: R40
title: Privileges of target sudo users
description: The targeted users of a rule should be, as much as possible, non privileged users.
levels:
- intermediary
status: automated
rules:
- sudoers_no_root_target
- id: R41
title: Limiting the number of commands requiring the use of the EXEC option
levels:
- enhanced
description: >-
The commands requiring the execution of sub-processes (EXEC tag) must be
explicitly listed and their use should be reduced to a strict minimum.
notes: >-
Human review is required to assess if the set of commands requiring EXEC is minimal.
An auxiliary rule could list rules containing EXEC tag, for analysis.
status: manual
- id: R42
title: Good use of negation in a sudoers file
levels:
- intermediary
description: The sudoers configuration rules should not involve negation.
status: automated
rules:
- sudoers_no_command_negation
- id: R43
title: Explicit arguments in sudo specifications
levels:
- intermediary
status: automated
rules:
- sudoers_explicit_command_args
- id: R44
title: Editing files with sudo
levels:
- intermediary
description: A file requiring sudo to be edited, must be edited through the sudoedit command.
notes: >-
In R62 we established that the sudoers files should not use negations, thus the approach
for this requirement is to ensure that sudoedit is the only text editor allowed.
But it is difficult to ensure that allowed binaries aren't text editors without human
review.
status: manual
- id: R45
title: Enable AppArmor security profiles
levels:
- enhanced
description: >-
All AppArmor security profiles on the system must be enabled by default.
status: automated
rules:
- apparmor_configured
- all_apparmor_profiles_enforced
- grub2_enable_apparmor
- package_apparmor_installed
- package_pam_apparmor_installed
- id: R46
title: Activate SELinux with the Targeted Policy
levels:
- high
description: >-
It is recommended to enable the targeted policy when the distribution
supports it and that it does not operate another security module than SELinux.
status: automated
rules:
- selinux_policytype
- var_selinux_policy_name=targeted
- id: R47
title: Containment of unprivileged interactive users
levels:
- high
description: >-
Interactive non-privileged users of a system must be confined by associating them with a SELinux
confined user.
notes: Interactive users who still need to perform administrative tasks should not be confined
with user_u.
status: manual
- id: R48
title: Setting SELinux booleans
levels:
- high
description: >-
It is recommended to set the following Booleans:
allow_execheap to off, forbids processes to make their heap executable;
allow_execmem to off, forbids processes to have both write and execute rights on memory pages;
allow_execstack to off, forbids processes to make their stack executable;
secure_mode_insmod to on, prohibits dynamic loading of modules by any process;
ssh_sysadm_login to off, forbids SSH logins to connect directly in sysadmin role.
notes: In RHEL, the SELinux boolean allow_execheap is renamed to selinuxuser_execheap, and the
boolean allow_execstack is renamed to selinuxuser_execstack. And allow_execmem is not available,
deny_execmem provides the same functionality.
status: automated
rules:
- var_selinuxuser_execheap=off
- sebool_selinuxuser_execheap
- var_deny_execmem=on
- sebool_deny_execmem
- var_selinuxuser_execstack=off
- sebool_selinuxuser_execstack
- var_secure_mode_insmod=on
- sebool_secure_mode_insmod
- sebool_ssh_sysadm_login
- id: R49
title: Uninstalling SELinux Policy Debugging Tools
levels:
- high
description: >-
SELinux policy manipulation and debugging tools should not be installed
on a machine in production.
status: automated
rules:
- package_setroubleshoot_removed
- package_setroubleshoot-server_removed
- package_setroubleshoot-plugins_removed
- id: R50
title: Rights to access sensitive files and directories
levels:
- intermediary
status: automated
rules:
- file_owner_etc_shadow
- file_groupowner_etc_shadow
- file_permissions_etc_shadow
- file_owner_etc_gshadow
- file_groupowner_etc_gshadow
- file_permissions_etc_gshadow
- file_owner_etc_passwd
- file_groupowner_etc_passwd
- file_permissions_etc_passwd
- file_owner_etc_group
- file_groupowner_etc_group
- file_permissions_etc_group
- file_owner_etc_shells
- file_groupowner_etc_shells
- file_permissions_etc_shells
- accounts_user_dot_group_ownership
- accounts_user_dot_user_ownership
- accounts_users_home_files_groupownership
- accounts_users_home_files_ownership
- accounts_users_home_files_permissions
- file_permission_user_init_files
- dir_system_commands_group_root_owned
- dir_system_commands_root_owned
- file_groupownership_system_commands_dirs
- file_ownership_binary_dirs
- file_permissions_binary_dirs
- file_ownership_sshd_private_key
- file_groupownership_sshd_private_key
- file_permissions_sshd_private_key
- file_ownership_sshd_pub_key
- file_groupownership_sshd_pub_key
- file_permissions_sshd_pub_key
- file_owner_sshd_config
- file_groupowner_sshd_config
- file_permissions_sshd_config
- directory_owner_etc_selinux
- directory_groupowner_etc_selinux
- directory_permissions_etc_selinux
- file_owner_etc_sestatus_conf
- file_groupowner_etc_sestatus_conf
- file_permissions_etc_sestatus_conf
- directory_owner_etc_ipsecd
- directory_groupowner_etc_ipsecd
- directory_permissions_etc_ipsecd
- file_owner_etc_ipsec_conf
- file_groupowner_etc_ipsec_conf
- file_permissions_etc_ipsec_conf
- file_owner_etc_ipsec_secrets
- file_groupowner_etc_ipsec_secrets
- file_permissions_etc_ipsec_secrets
- directory_owner_etc_iptables
- directory_groupowner_etc_iptables
- directory_permissions_etc_iptables
- directory_owner_etc_nftables
- directory_groupowner_etc_nftables
- directory_permissions_etc_nftables
- directory_owner_etc_sysctld
- directory_groupowner_etc_sysctld
- directory_permissions_etc_sysctld
- file_owner_etc_sudoers
- file_groupowner_etc_sudoers
- file_permissions_etc_sudoers
- directory_owner_etc_sudoersd
- directory_groupowner_etc_sudoersd
- directory_permissions_etc_sudoersd
- file_owner_etc_crypttab
- file_groupowner_etc_crypttab
- file_permissions_etc_crypttab
- file_owner_etc_chrony_keys
- file_groupowner_etc_chrony_keys
- file_permissions_etc_chrony_keys
- id: R51
title: Sensitive and trusted files
levels:
- enhanced
description: >-
All sensitive files and those contributing to the authentication mechanisms
must be set up as soon as the system is installed. If default secrets are
preconfigured, they must be replaced during, or immediately after, the
installation phase of the system.
notes: >-
This concerns two aspects, the first is administrative, and involves prompt
installation of secrets or trusted elements by the sysadmin.
The second involves removal of any default secret or trusted element
configured by the operating system during install process, e.g. default
known passwords.
status: documentation
- id: R52
title: Securing access for named sockets and pipes
levels:
- intermediary
notes: |-
The requirement states that all sockets and named pipes within all mounted
file systems should be checked. The check should look at the permissions
of the socket / pipe and compare them with permissions of the directory
which contains the particular socket. In case permissions of the directory
are less stricter than permissions of the socket, this should be
considered a finding. Since different use cases can require different
permissions for named pipes / sockets, it is not possible to perform this
check automatically.
status: manual
- id: R53
title: Files or directories without a known user or group
levels:
- minimal
status: automated
rules:
- file_permissions_ungroupowned
- no_files_unowned_by_user
- id: R54
title: Sticky bit and write access rights
levels:
- minimal
status: automated
rules:
- dir_perms_world_writable_sticky_bits
- dir_perms_world_writable_root_owned
- file_permissions_unauthorized_world_writable
- id: R55
title: Temporary directories dedicated to accounts
levels:
- intermediary
description: >-
Each user or service account must have its own temporary directory
and dispose of it exclusively.
notes: The approach of the selected rules is to use and configure pam_namespace module.
status: automated
rules:
- enable_pam_namespace
- accounts_polyinstantiated_tmp
- accounts_polyinstantiated_var_tmp
- var_polyinstantiation_enabled=on
- sebool_polyinstantiation_enabled
- id: R56
title: Executables with setuid and setgid bits
levels:
- minimal
notes: >-
Only programs specifically designed to be used with setuid or setgid bits can have these privilege
bits set.
This requirement considers apropriate for setuid and setgid bits the binaries that are installed
from
recognized and authorized repositories (covered in R15).
The remediation resets the sticky bit to intended value by vendor/developer, any finding after
remediation
should be reviewed.
status: automated
rules:
- file_permissions_unauthorized_suid
- file_permissions_unauthorized_sgid
- id: R57
title: Executable with special rights setuid root and setgid root
levels:
- enhanced
description: >-
The executables with setuid executables root and setgid root special rights should be as few
as possible.
When only administrators are expected to execute them, these special rights should
be removed and prefer them commands like su or sudo, which can be monitored
notes: There could be rules to list all executables with setuid root or setgid root rights.
status: manual
- id: R58
title: Installation of packages reduced to the bare necessities
levels:
- minimal
description: >-
The selection of packages installed should be as small as possible,
limiting itself to select only what is required.
notes: >-
It is not possible to automatically decide in general way if a package is required or not for
given system.
As a future improvement, there could be rules assisting assessment by listing the installed
packages.
status: manual
- id: R59
title: Official package repositories
levels:
- minimal
description: Only up-to-date official repositories of the distribution must be used.
notes: >-
It is not trivial to distinguish an official repository from an unofficial one.
We cannot draw conclusions from the repo name or URL of the repo (as they can be arbitrary
or behind a proxy).
One approach to check the origin of installed packages is to check the signature of the packages.
If the public key of a repository is not installed, the repo is not trusted.
status: automated
rules:
- ensure_gpgcheck_never_disabled
- ensure_gpgcheck_globally_activated
- ensure_gpgcheck_local_packages
- ensure_redhat_gpgkey_installed
- ensure_oracle_gpgkey_installed
- ensure_almalinux_gpgkey_installed
- id: R60
title: Hardened package repositories
levels:
- enhanced
description: >-
When the distribution provides several types of repositories, preference
should be given to those containing packages subject to additional
hardening measures.
Between two packages providing the same service, those subject to hardening
(at compilation, installation, or default configuration) must be preferred.
status: not applicable
- id: R61
title: Regular updates
levels:
- minimal
notes: Check the vendor CVE feed and configure automatic install of security related updates.
status: automated
rules:
- security_patches_up_to_date
- package_dnf-automatic_installed
- timer_dnf-automatic_enabled
# Configure dnf-automatic to Install Available Updates Automatically
- dnf-automatic_apply_updates
# Configure dnf-automatic to Install Only Security Updates
- dnf-automatic_security_updates_only
- id: R62
title: Minimization of installed services
levels:
- minimal
description: >-
Only the components strictly necessary to the service provided by the system should
be installed.
Those whose presence can not be justified should be disabled, removed or deleted.
status: manual # The list of essential services is not objective.
notes: >-
Performing a minimal install is a good starting point, but doesn't provide any assurance
over any package installed later.
Manual review is required to assess if the installed services are minimal.
In general, use of obsolete or insecure services is not recommended and we remove some
of these in this recommendation.
rules:
- package_dhcp_removed
- package_kea_removed
- package_rsh_removed
- package_rsh-server_removed
- package_sendmail_removed
- package_talk_removed
- package_talk-server_removed
- package_telnet_removed
- package_telnet-server_removed
- package_tftp_removed
- package_tftp-server_removed
- package_xinetd_removed
- package_ypbind_removed
- package_ypserv_removed
- id: R63
title: Minimization of services configuration
levels:
- intermediary
description: >-
Services are often installed with default configurations that enable features potentially
problematic from a security point of view.
The features configured at the level of launched services should be limited to the strict
minimum.
notes: >-
Define a list of most problematic components or features to be hardened or restricted.
status: manual
- id: R64
title: Least privilege for the services
levels:
- enhanced
description: >-
The deployed services must have their access restricted to the system
strict minimum, especially when it comes to files, processes or network.
notes: >-
SELinux policies limit the privileges of services and daemons just to those which are required.
The policies should be enough to restrict the services' privileges to its essentials, but the
automated content cannot assess whether they are the minimum required for the deployment.
status: automated
rules:
- selinux_policytype
- var_selinux_policy_name=targeted
- id: R65
title: Services partitioning
levels:
- enhanced
notes: >-
Using automation to restrict access and chroot services is not generally reliable.
status: manual
- id: R66
title: Virtualization components hardening
levels:
- high
description: >-
Each component supporting the virtualization must be hardened, especially
by applying technical measures to counter the exploit attempts.
notes: >-
We cannot easily automate securing of virtualization technologies in a general way.
It may be interesting to point out virtualization components that are installed and
should be hardened.
status: manual
- id: R67
title: Secure remote authentication with PAM
levels:
- intermediary
description: |-
When authentication takes place through a remote application (network),
the authentication protocol used by PAM must be secure (flow encryption,
remote server authentication, anti-replay mechanisms, ...).
notes: |-
In systems where remote authentication is handled through sssd service, PAM delegates
requests for remote authentication to sssd service through a local Unix socket. The sssd
service can use IPA, AD or LDAP as a remote database containing information required for authentication.
In case LDAP is configured manually, there are several configuration options which should be chedked.
status: automated
rules:
- package_sssd_installed
- service_sssd_enabled
- sssd_enable_pam_services
- sssd_ldap_configure_tls_reqcert
- sssd_ldap_start_tls
related_rules:
- package_sssd-ipa_installed
- id: R68
title: Protecting stored passwords
levels:
- minimal
description: Any password must be protected by cryptographic mechanisms.
notes: >-
The selection of rules doesn't cover the use of hardware devices to protect the passwords.
status: supported
rules:
- var_password_hashing_algorithm=yescrypt
- var_password_hashing_algorithm_pam=sha512
- set_password_hashing_algorithm_systemauth
- var_password_pam_unix_rounds=11
- accounts_password_pam_unix_rounds_system_auth
- accounts_password_pam_unix_rounds_password_auth
- accounts_password_pam_minclass
- accounts_password_pam_minlen
- accounts_password_pam_retry
- var_password_pam_minclass=4
- id: R69
title: Securing access to remote user databases
levels:
- intermediary
description: |-
When the user databases are stored on a remote network service, NSS must
be configured to establish a secure link that allows, at minimum, to
authenticate the server and protect the communication channel.
notes: |-
A nsswitch service connecting to remote database is provided by sssd. This is checked in requirement R67.
Another such service is winbind which is by default configured to connect securely to Samba domains.
Other relevant services are NIS and Hesiod. These should not be used.
status: pending
related_rules:
- no_nis_in_nsswitch
- id: R70
title: Separation of System Accounts and Directory Administrator
levels:
- intermediary
status: manual
- id: R71
title: Implement a logging system
levels:
- enhanced
description: >-
The configuration of the service must be performed according to the
'Security Recommendations for the architecture of a logging system'
(DAT-PA-012 v2.0) accessible on the ANSSI website
(https://www.ssi.gouv.fr/journalisation).
notes: >-
A lot of recommendations and requirements from the DAT-PA-012 document are administrative and
hard to automate.
The rules selected below address a few of the aspects that can be covered, keep in mind that
these configurations should
be customized for the systems deployment requirements.
status: automated
rules:
# Based on DAT-PA-012 R5
- package_chrony_installed
- service_chronyd_or_ntpd_enabled
- chronyd_specify_remote_server
- chronyd_configure_pool_and_server
# Derived from DAT-PA-012 R9
# The default remote loghost is logcollector.
# Change the default value to the hostname or IP of the system to send the logs to
- rsyslog_remote_loghost
# Derived from DAT-PA-012 R17
- package_rsyslog-gnutls_installed
- rsyslog_remote_tls
- rsyslog_remote_tls_cacert
# Derived from DAT-PA-012 R21
- partition_for_var_log_audit
# Based on DAT-PA-012 R24
# The rules sets the rotation frequency to daily
- package_logrotate_installed
- timer_logrotate_enabled
- ensure_logrotate_activated
# Based on DAT-PA-012 R26, R27
- rsyslog_files_ownership
- rsyslog_files_groupownership
- rsyslog_files_permissions
- id: R72
title: Service Activity Logs
levels:
- enhanced
description: >-
Each service must have a dedicated event logging journal on the system.
This log must only be accessible by the syslog server, and must not be readable,
editable or deletable by the service directly.
status: documentation # How to enable syslog for each service installed in the system
- id: R73
title: Logging activity by auditd
levels:
- enhanced
description: >-
The logging of the system activity must be done through the auditd service.
status: automated
rules:
- audit_rules_sysadmin_actions
- audit_sudo_log_events
- audit_rules_login_events_faillock
- audit_rules_login_events_lastlog
- audit_rules_session_events_utmp
- audit_rules_session_events_btmp
- audit_rules_session_events_wtmp
- audit_rules_time_adjtimex
- audit_rules_time_clock_settime
- audit_rules_time_stime
- audit_rules_time_watch_localtime
- audit_rules_mac_modification
- audit_rules_networkconfig_modification
- audit_rules_dac_modification_chmod
- audit_rules_dac_modification_chown
- audit_rules_dac_modification_fchmod
- audit_rules_dac_modification_fchmodat
- audit_rules_dac_modification_fchmodat2
- audit_rules_dac_modification_fchown
- audit_rules_dac_modification_fchownat
- audit_rules_dac_modification_fremovexattr
- audit_rules_dac_modification_fsetxattr
- audit_rules_dac_modification_lchown
- audit_rules_dac_modification_lremovexattr
- audit_rules_dac_modification_lsetxattr
- audit_rules_dac_modification_removexattr
- audit_rules_dac_modification_setxattr
- audit_rules_unsuccessful_file_modification_creat
- audit_rules_unsuccessful_file_modification_ftruncate
- audit_rules_unsuccessful_file_modification_open
- audit_rules_unsuccessful_file_modification_openat
- audit_rules_unsuccessful_file_modification_truncate
- audit_rules_usergroup_modification_group
- audit_rules_usergroup_modification_gshadow
- audit_rules_usergroup_modification_opasswd
- audit_rules_usergroup_modification_passwd
- audit_rules_usergroup_modification_shadow
- audit_rules_media_export
- audit_rules_dac_modification_umount2
- audit_rules_privileged_commands
- audit_rules_file_deletion_events_rename
- audit_rules_file_deletion_events_renameat
- audit_rules_file_deletion_events_renameat2
- audit_rules_file_deletion_events_rmdir
- audit_rules_file_deletion_events_unlink
- audit_rules_file_deletion_events_unlinkat
- audit_rules_kernel_module_loading_delete
- audit_rules_kernel_module_loading_init
- audit_rules_kernel_module_loading_finit
- audit_rules_privileged_commands_insmod
- audit_rules_privileged_commands_modprobe
- audit_rules_privileged_commands_rmmod
- audit_rules_privileged_commands_kmod
- audit_rules_immutable
- service_auditd_enabled
- package_audit_installed
- id: R74
title: Configuring the local messaging service
levels:
- intermediary
status: automated
rules:
- postfix_network_listening_disabled
- id: R75
title: Messaging Aliases for Service Accounts
levels:
- intermediary
status: automated # semi-automated
notes: >-
Only the alias for root user is covered by the rule.
The other services cannot be reliably covered, as there is no simple way
of determining what is a service account.
rules:
- postfix_client_configure_mail_alias
- id: R76
title: Sealing and integrity of files
levels:
- high
description: >-
Any file that is not transient (such as temporary files, databases, etc.)
must be monitored by a sealing program.
This includes: directories containing executables, libraries,
configuration files, as well as any files that may contain sensitive
elements (cryptographic keys, passwords, confidential data).
status: automated
rules:
- package_aide_installed
- aide_build_database
- aide_periodic_cron_checking
- aide_periodic_checking_systemd_timer
- aide_scan_notification
- aide_verify_acls
- aide_verify_ext_attributes
- id: R77
title: Protection of the seals database
levels:
- high
description: >-
The sealing database must be protected from malicious access by
cryptographic signature mechanisms (with the key used for the signature
not locally stored in clear), or possibly stored on a separate machine
of the one on which the sealing is done.
Check section "Database and config signing in AIDE manual"
https://aide.github.io/doc/#signing
status: does not meet
- id: R78
title: Network services partitioning
levels:
- enhanced
description: >-
Network services should as much as possible be hosted on isolated environments.
This avoids having other potentially affected services if one of them gets
compromised under the same environment.
notes: >-
Manual analysis is required to determine if services are hosted appropriately in
separate or isolated system while maintaining functionality.
status: manual
- id: R79
title: Hardening and monitoring of exposed services
levels:
- intermediary
notes: >-
SELinux can provide confinement and monitoring of services, and AIDE provides
basic integrity checking. System logs are configured as part of R43.
Hardening of particular services should be done on a case by case basis and is
not automated by this content.
status: partial
rules:
- selinux_state
- var_selinux_state=enforcing
- package_aide_installed
- aide_build_database
- id: R80
title: Minimization of network services
levels:
- minimal
description: All network services must be listening on the correct network intefaces.
notes: >-
Manual review is necessary to decide if the list of resident daemons is minimal.
Assisting rules could be created to list sevices listening on the network for manual review.
status: manual
|