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
|
#This file was created by <camille> Thu Jan 6 11:15:42 2000
#LyX 0.12 (C) 1995-1998 Matthias Ettrich and the LyX Team
\lyxformat 2.15
\textclass article
\language american
\inputencoding latin1
\fontscheme default
\graphics default
\paperfontsize default
\spacing single
\papersize Default
\paperpackage a4
\use_geometry 0
\use_amsmath 0
\paperorientation portrait
\secnumdepth 3
\tocdepth 3
\paragraph_separation skip
\defskip medskip
\quotes_language english
\quotes_times 2
\papercolumns 1
\papersides 2
\paperpagestyle default
\layout Title
\size huge
msec
\size default
\noun on
[Mandrake SECurity tools]
\layout Author
Camille Bégnis <camille@mandrakesoft.com>
\layout Date
22/12/1999
\layout Standard
\begin_inset LatexCommand \tableofcontents
\end_inset
\layout Section
Introducing msec
\layout Standard
While Linux is being used for a very wide range of applications, from basic
office work to high availability servers, came the need for different security
levels.
It is obvious that constraints inherent to highly secured servers do not
match the needs of a secretary.
In the other hand a big public server is more sensitive to malicious people
than my isolated Linux box.
\layout Standard
It is in that aim that were designed the msec package.
It is made of two parts:
\layout Enumerate
Scripts that modify the whole system to lead it to one of the six security
levels provided with msec.
These levels range from very poor security and ease of use, to paranoid
config, suitable for very sensitive applications, managed by experts.
\layout Enumerate
Cron jobs, that will periodically check the integrity of the system upon
security level configuration, and eventually detect and warn you of possible
intrusion of the system or security leak.
\layout Standard
Note that the user may also define his own security level, adjusting parameters
to his own needs.
\layout Section
Installation
\layout Standard
msec is a base rpm.
That means that if you previously installed Linux-Mandrake, msec is already
installed on your system.
\layout Standard
Installing the rpm will create a msec directory into /etc/security, containing
all is needed to secure your system.
\layout Standard
Then just login as root and type
\begin_inset Quotes erd
\end_inset
/usr/sbin/msec x
\begin_inset Quotes erd
\end_inset
, x being the security level you want or
\begin_inset Quotes eld
\end_inset
custom
\begin_inset Quotes erd
\end_inset
to create your own security level.
The script will begin to remove all modifications made by a previous security
level change, and apply the features of the chosen security level to your
system.
If you choose
\begin_inset Quotes eld
\end_inset
custom
\begin_inset Quotes erd
\end_inset
, then you will be asked a series of questions for each security feature
msec proposes.
At the end, these features will be applied to your system.
\layout Standard
Note that whatever the level you chose, your configuration will be stored
into
\begin_inset Quotes eld
\end_inset
/etc/security/msec/security.conf
\begin_inset Quotes erd
\end_inset
.
\layout Subsection
Level 0
\begin_inset Quotes eld
\end_inset
Welcome To Crackers
\begin_inset Quotes erd
\end_inset
\layout Standard
This level is to be used with care.
It makes your system more easy to use, but very sensitive at the same time.
In particular, you shouldn't use this security level if you answer yes
to at least one of the following questions:
\layout Itemize
Is my computer connected to the Internet?
\layout Itemize
Is my computer connected to other computers by a network?
\layout Itemize
Does this computer will be used by someone else than me?
\layout Itemize
Is there some confidential stuff on my computer I don't want others have
access?
\layout Itemize
I don't know Linux enough and I could harm it by myself?
\layout Standard
As we see, this security level shouldn't be set by default because it may
result in big problems for your data.
\layout Subsection
Level 1
\begin_inset Quotes eld
\end_inset
Poor
\begin_inset Quotes erd
\end_inset
\layout Standard
The main security improvement compared with level 0 is that now, the access
to one user's stuff is granted via user-name and password.
So it may be used by various people, and it is less sensitive to bad maneuvers.
However it shouldn't be used for a connected computer whether by modem
or to a LAN (Local Area Network).
\layout Subsection
Level 2
\begin_inset Quotes eld
\end_inset
Low
\begin_inset Quotes erd
\end_inset
\layout Standard
Few improvements for this security level, the main one is that there are
more security warnings and checks.
It is more secure for multi-users use.
\layout Subsection
Level 3
\begin_inset Quotes erd
\end_inset
Medium
\begin_inset Quotes erd
\end_inset
\layout Standard
This is the standard security recommended for a computer that will be used
to connect to the Internet as a client.
Most of security checks are periodically run, specifically one that check
for open ports on the system.
However, these open ports are kept opened and access to them is granted
to everyone.
So this security level is not really suited for a system permanently connected
to the Internet.
\layout Standard
From the user's point of view, the system is now a little bit more closed,
so it'll need some basic knowledges of the Linux system to achieve some
special operations.
The security here offered is comparable with the one of a standard RedHat
or previous Mandrake distribution.
\layout Subsection
Level 4
\begin_inset Quotes eld
\end_inset
High
\begin_inset Quotes erd
\end_inset
\layout Standard
With this security level, the use of this system as a server becomes possible.
The security is now high enough to use the system as a server which accept
connections from many clients.
Connections from the computer itself only will be granted.
Howether advanced services have been disabled, and the system administrator
will have to activate the desired ones by hand in config files.
He also will have to define from whom the access is granted.
\layout Standard
Security checks will warn system administrator of possible security holes
or intrusions on the system.
\layout Subsection
Level 5
\begin_inset Quotes eld
\end_inset
Paranoid
\begin_inset Quotes erd
\end_inset
\layout Standard
We take level 4 features, but now the system is entirely closed.
Security features are at their maximum.
The system administrator has to activate ports, and grant connections to
give other computers access to services offered by this machine.
\layout Section
Security levels features
\layout Standard
Follows the description of the different security features each level brings
to the system.
These features are of various types:
\layout Itemize
file permissions,
\layout Itemize
warnings dispatching,
\layout Itemize
periodicall security checks:
\layout Quotation
- on files: suid root, writable, unowned;
\layout Quotation
- listening ports: active, promiscuous;
\layout Quotation
- passwords files.
\layout Itemize
X display connections,
\layout Itemize
listening port check,
\layout Itemize
services available,
\layout Itemize
boot password,
\layout Itemize
authorized clients.
\layout Standard
\LyXTable
multicol5
28 7 0 0 -1 -1 -1 -1
1 1 0 0
1 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
0 1 0 0
2 1 0 "50mm" ""
8 1 0 "" ""
8 1 0 "" ""
8 1 0 "" ""
8 1 0 "" ""
8 1 0 "" ""
8 1 1 "" ""
0 2 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 2 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 2 0 1 0 0 0 "" ""
0 2 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 2 0 1 0 0 0 "" ""
0 2 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
0 8 0 1 0 0 0 "" ""
\series bold
\emph on
Feature
\backslash
Security level
\newline
0
\newline
1
\newline
2
\newline
3
\newline
4
\newline
5
\series default
\emph toggle
\newline
Global security check
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
*
\newline
umask users
\newline
002
\newline
002
\newline
022
\newline
022
\newline
077
\newline
077
\newline
umask root
\newline
002
\newline
002
\newline
022
\newline
022
\newline
022
\newline
077
\newline
shell without password
\newline
*
\newline
\newline
\newline
\newline
\newline
\newline
authorized to connect to X display
\newline
all
\newline
local
\newline
local
\newline
none
\newline
none
\newline
none
\newline
User in audio group
\newline
*
\newline
*
\newline
*
\newline
\newline
\newline
\newline
.
in $PATH
\newline
*
\newline
*
\newline
\newline
\newline
\newline
\newline
Warning in /var/log/security.log
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
*
\newline
Warning directly on tty
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
Warning in syslog
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
Warning sent by mail to root
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
Suid root file check
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
Suid root file md5sum check
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
Writable file check
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
*
\newline
Permissions check
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
Suid group file check
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
Unowned file check
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
Promiscuous check
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
Listening port check
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
Passwd file integrity check
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
Shadow file integrity check
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
System security check every midnight
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
All system events additionally logged to /dev/tty12
\newline
\newline
\newline
\newline
*
\newline
*
\newline
*
\newline
Only root can
\begin_inset Quotes eld
\end_inset
ctrl-alt-del
\begin_inset Quotes erd
\end_inset
\newline
\newline
\newline
\newline
\newline
*
\newline
*
\newline
Services not known disabled
\newline
\newline
\newline
\newline
\newline
*
\newline
*
\newline
Boot password
\newline
\newline
\newline
\newline
\newline
*
\newline
*
\newline
Grant connection to
\newline
all
\newline
all
\newline
all
\newline
all
\newline
local
\newline
none
\layout Standard
Note that six out of the ten periodical checks can detect changes on the
system.
They store into files located in
\begin_inset Quotes eld
\end_inset
/var/log/security/
\begin_inset Quotes erd
\end_inset
the configuration of the system during the last check (one day ago), and
warn you of any changes occurred meanwhile.
These checks are:
\layout Itemize
Suid root file check
\layout Itemize
Suid root file md5sum check
\layout Itemize
Writable file check
\layout Itemize
Suid group file check
\layout Itemize
Unowned file check
\layout Itemize
Listening port check
\layout Subsection
Global security check
\layout Itemize
NFS filesystems globally exported.
This is regarded as insecure, as there is no restriction for who may mount
these filesystems
\layout Itemize
NFS mounts with missing nosuid.
These filesystems are exported without the
\begin_inset Quotes eld
\end_inset
nosuid
\begin_inset Quotes erd
\end_inset
option.
\layout Itemize
Host trusting files contains
\begin_inset Quotes eld
\end_inset
+
\begin_inset Quotes erd
\end_inset
sign.
That means that one of the files
\begin_inset Quotes eld
\end_inset
/etc/hosts.equiv /etc/shosts.equiv /etc/hosts.lpd
\begin_inset Quotes erd
\end_inset
is containing hosts which are allowed to connect without proper authentication.
\layout Itemize
Executables found in the aliases file.
It issues a warning naming the executables run through files "/etc/aliases
\begin_inset Quotes erd
\end_inset
and
\begin_inset Quotes eld
\end_inset
/etc/postfix/aliases".
\layout Subsection
umask users
\layout Standard
Simply sets the umask for normal users to the value corresponding to the
security level.
\layout Subsection
umask root
\layout Standard
The same but for the root.
\layout Subsection
shell without password
\layout Standard
Access to the consoles is granted without asking for a password.
\layout Subsection
authorized to connect to X display
\layout Itemize
all : Everybody from everywhere can open an X window on your screen.
\layout Itemize
local : Only people connected at localhost may open an X window on your
screen.
\layout Itemize
none : Nobody can do that.
\layout Subsection
User in audio group
\layout Standard
Each user is a member of the
\begin_inset Quotes eld
\end_inset
audio
\begin_inset Quotes erd
\end_inset
group.
That means that every user connected to the system is given access to sound
card.
\layout Subsection
.
in $PATH
\layout Standard
the
\begin_inset Quotes eld
\end_inset
.
\begin_inset Quotes erd
\end_inset
entry is added to $PATH environment variable, allowing execution of programs
within the current working directory.
\layout Subsection
Warning in /var/log/security.log
\layout Standard
Each warning issued by msec is logged into
\begin_inset Quotes eld
\end_inset
/var/log/security.log
\begin_inset Quotes erd
\end_inset
.
\layout Subsection
Warning directly on tty
\layout Standard
Each warning issued by msec is directly printed on current console.
\layout Subsection
Warning in syslog
\layout Standard
Warnings of msec are directed to syslog service.
\layout Subsection
Warning sent by mail to root
\layout Standard
Warnings issued by msec are also sent by mail to root.
\layout Subsection
Suid root file check
\layout Standard
Check for new or removed suid root files on the system.
If such files are encountered a list of these files is issued as a warning.
\layout Subsection
Suid root file md5sum check
\layout Standard
Checks the md5sum signature of each suid root file that is on the system.
If the signature has changed, it means that a modification has been made
to this program, probably a backdoor.
A warning is then issued.
\layout Subsection
Writable file check
\layout Standard
Check wether files are world writable on the system.
If so, issues a warning containing the list of these naughty files.
\layout Subsection
Permissions check
\layout Standard
This one checks permissions for some special files such as .netrc or user's
config files.
It also checks permissions of users home dir.
If their permissions are too loose or owners unusual, it issues a warning.
\layout Subsection
Suid group file check
\layout Standard
Check for new or removed suid group files on the system.
If such files are encountered, a list of these files is issued as a warning.
\layout Subsection
Unowned file check
\layout Standard
This check searches for files owned by users/groups(or more accurately by
uids/gids) not known into /etc/password, If such files are found, the owner
is automatically changed to user/group
\begin_inset Quotes eld
\end_inset
nobody
\begin_inset Quotes erd
\end_inset
.
\layout Subsection
Promiscuous check
\layout Standard
This test checks every ethernet card to determine wether they are in promiscuous
mode.
This mode allows the card to intercept every packet received by the card,
even those that are not directed to it.
It may mean that a sniffer is running on your machine.
\layout Standard
Note that this check is setted up to be run every minute.
\layout Subsection
Listening port check
\layout Standard
Issues a warning with all listening ports.
\layout Subsection
Passwd file integrity check
\layout Standard
Verify that each user has a password ( no blank password) and if it is shadowed.
\layout Subsection
Shadow file integrity check
\layout Standard
Verify that each user into the shadow file has a password ( no blank password).
\layout Subsection
System security check every midnight
\layout Standard
All previous checks will be performed everyday at midnight.
This relies on the addition of cron scripts in crontab file.
\layout Subsection
All system events additionally logged to /dev/tty12
\layout Standard
*All* system messages directed to syslog are copied to tty12 console.
\layout Subsection
Only root can
\begin_inset Quotes eld
\end_inset
ctrl-alt-del
\begin_inset Quotes erd
\end_inset
\layout Standard
Root (or a user referenced into /etc/shutdown.allow) must be logged into
a console for the key binding
\begin_inset Quotes eld
\end_inset
ctrl-alt-del
\begin_inset Quotes erd
\end_inset
having effect.
If no privileged user is logged, nothing happens when someone uses
\begin_inset Quotes eld
\end_inset
ctrl-alt-del
\begin_inset Quotes erd
\end_inset
.
\layout Subsection
Services not known disabled
\layout Standard
All services not contained into
\begin_inset Quotes eld
\end_inset
/etc/security/msec/server.4
\begin_inset Quotes erd
\end_inset
for level 4 or
\begin_inset Quotes eld
\end_inset
server.5
\begin_inset Quotes erd
\end_inset
for level 5 will be disabled.
They are not removed, but simply not started when loading a runlevel.
If you need some of them, just add them again with the
\begin_inset Quotes eld
\end_inset
chkconfig
\begin_inset Quotes erd
\end_inset
utility (you might also need to restart them with init scripts in /etc/rc.d/init.
d/ ).
\layout Subsection
Boot password
\layout Standard
Allows you to setup a password for Lilo.
Prevents (unexperienced) people from rebooting the machine, but in the
other hand, the machine won't be able to reboot by itself.
\layout Subsection
Grant connection to
\layout Itemize
all : All computers are allowed to connect to open ports.
\layout Itemize
local : Only the localhost is allowed to connect to open ports.
\layout Itemize
none : No computers are allowed to connect to open ports.
\layout Section
ToDo
\layout Standard
- Automatic tty locking ( unlock by passwd ) after X time of inactivity.
\layout Standard
- In high security level, only user having access to group "sugrp" can use
the su command.
\layout Section
Author
\layout Standard
Vandoorselaere Yoann
\the_end
|