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
|
#!/bin/sh
#################################################################################
#
# Lynis
# ------------------
#
# Website : https://cisofy.com
# Blog : http://linux-audit.com
# GitHub : https://github.com/CISOfy/lynis
#
# Lynis comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
# welcome to redistribute it under the terms of the GNU General Public License.
# See LICENSE file for usage of this software.
#
#################################################################################
#
# USB Devices
#
#################################################################################
#
InsertSection "USB Devices"
#
#################################################################################
#
USBGUARD_FOUND=0
USBGUARD_CONFIG=""
USBGUARD_RULES=""
USBGUARD_RESTORE_POLICY=""
USBGUARD_CONTROLLER_POLICY=""
USBGUARD_DEVICE_POLICY=""
USBGUARD_INSERTED_POLICY=""
USBGUARD_DEFAULT_POLICY=""
USBGUARD_RULES_ALLOW=0
USBGUARD_RULES_BLOCK=0
USBGUARD_RULES_REJECT=0
#
#################################################################################
#
# Test to determine if USBGuard is installed. If it is, we will limit
# suggestions from other tests.
if [ -n "${USBGUARDBINARY}" ]; then
USBGUARD_FOUND=1
fi
#
#################################################################################
#
# Test : USB-1000 (was STRG-1840)
# Description : Check for disabled USB storage
Register --test-no USB-1000 --os Linux --weight L --network NO --category security --description "Check if USB storage is disabled"
if [ ${SKIPTEST} -eq 0 ]; then
FOUND=0
LogText "Test: Checking USB storage driver in directory /etc/modprobe.d and configuration file /etc/modprobe.conf"
if [ -d /etc/modprobe.d ]; then
FIND=$(${LSBINARY} ${ROOTDIR}etc/modprobe.d/* 2> /dev/null)
if [ -n "${FIND}" ]; then
FIND=$(${EGREPBINARY} -r "install usb[-_]storage /bin/(false|true)" ${ROOTDIR}etc/modprobe.d/* | ${GREPBINARY} -v "#")
FIND2=$(${EGREPBINARY} -r "^blacklist usb[-_]storage" ${ROOTDIR}etc/modprobe.d/*)
if [ -n "${FIND}" -o -n "${FIND2}" ]; then
FOUND=1
LogText "Result: found usb-storage driver in disabled state (blacklisted)"
fi
else
LogText "Result: uncommon situation. Found /etc/modprobe.d directory, but no files in it."
fi
fi
if [ -f ${ROOTDIR}etc/modprobe.conf ]; then
FIND=$(${EGREPBINARY} "install usb[-_]storage /bin/(false|true)" ${ROOTDIR}etc/modprobe.conf | ${GREPBINARY} "usb-storage" | ${GREPBINARY} -v "#")
if [ -n "${FIND}" ]; then
FOUND=1
LogText "Result: found usb-storage driver in disabled state"
fi
fi
if [ ${FOUND} -eq 0 ]; then
LogText "Result: usb-storage driver is not explicitly disabled"
Display --indent 2 --text "- Checking usb-storage driver (modprobe config)" --result "NOT DISABLED" --color WHITE
if [ "${USBGUARD_FOUND}" -eq "0" ]; then
ReportSuggestion ${TEST_NO} "Disable drivers like USB storage when not used, to prevent unauthorized storage or data theft"
fi
AddHP 2 3
else
LogText "Result: usb-storage driver is disabled"
Display --indent 2 --text "- Checking usb-storage driver (modprobe config)" --result "${STATUS_DISABLED}" --color GREEN
AddHP 3 3
fi
fi
#
#################################################################################
#
# Test : USB-2000 (was STRG-1842)
# Description : Check USB authorizations
Register --test-no USB-2000 --os Linux --weight L --network NO --category security --description "Check USB authorizations"
if [ ${SKIPTEST} -eq 0 ]; then
LogText "Test: Checking USB devices authorization to connect to the system"
FOUND=0
USBDEVICESPATH="${ROOTDIR}sys/bus/usb/devices/usb"
for device in "${USBDEVICESPATH}"*; do
if [ -e "${device}/authorized" -o -e "${device}/authorized_default" ]; then
if [ $(cat "${device}/authorized_default") -eq 1 ]; then
FOUND=1
LogText "Test: ${device} is authorized by default"
Report "usb_authorized_default_device[]=${device}"
elif [ $(cat "${device}/authorized") -eq 1 ]; then
FOUND=1
LogText "Test: ${device} is authorized currently"
Report "usb_authorized_device[]=${device}"
fi
else
LogText "Test: ${device} is authorized by default"
Report "usb_authorized_default_device[]=${device}"
FOUND=1
fi
done
if [ ${FOUND} -eq 1 ]; then
LogText "Result: Some USB devices are authorized by default (or temporary) to connect to the system"
Display --indent 2 --text "- Checking USB devices authorization" --result "${STATUS_ENABLED}" --color YELLOW
# To-Be-Added: create documentation and enable the suggestion
#if [ ${USBGUARD_FOUND} -eq 0 ]; then
# ReportSuggestion ${TEST_NO} "Disable USB devices authorization, to prevent unauthorized storage or data theft"
#fi
AddHP 0 3
else
LogText "Result: None USB devices are authorized by default (or temporary) to connect to the system"
Display --indent 2 --text "- Checking USB devices authorization" --result "${STATUS_DISABLED}" --color GREEN
AddHP 3 3
fi
fi
#
#################################################################################
#
# Test : USB-3000
# Description : Perform USBGuard check
Register --test-no USB-3000 --os Linux --weight L --network NO --category security --description "Check for presence of USBGuard"
if [ ${SKIPTEST} -eq 0 ]; then
if [ ${USBGUARD_FOUND} -eq 1 ]; then
LogText "Result: USBGuard is installed (${USBGUARDBINARY})"
Display --indent 2 --text "- Checking USBGuard" --result "${STATUS_FOUND}" --color GREEN
AddHP 1 1
LogText "Checking USBGuard configuration file"
if [ -f ${ROOTDIR}etc/usbguard/usbguard-daemon.conf ]; then
USBGUARD_CONFIG="${ROOTDIR}etc/usbguard/usbguard-daemon.conf"
else
USBGUARD_CONFIG=""
fi
if [ -n "${USBGUARD_CONFIG}" ]; then
LogText "Result: USBGuard configuration found (${USBGUARD_CONFIG})"
Display --indent 4 --text "- Configuration" --result "${STATUS_FOUND}" --color GREEN
AddHP 1 1
LogText "Checking USBGuard restore controller device state (RestoreControllerDeviceState)"
USBGUARD_RESTORE_POLICY=$(${AWKBINARY} -F '=' -v OPT="RestoreControllerDeviceState" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_RESTORE_POLICY}" ]; then
LogText "Result: RestoreControllerDeviceState = ${USBGUARD_RESTORE_POLICY}"
case "${USBGUARD_RESTORE_POLICY}" in
"true")
Display --indent 6 --text "- Restore controller device state" --result "${USBGUARD_RESTORE_POLICY}" --color YELLOW
LogText " Consider changing RestoreControllerDeviceState to \"false\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Consider hardening USBGuard configuration" "RestoreControllerDeviceState (${USBGUARD_RESTORE_POLICY} --> false)"
AddHP 0 1
;;
"false")
Display --indent 6 --text "- Restore controller device state" --result "${USBGUARD_RESTORE_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for RestoreControllerDeviceState"
Display --indent 6 --text "- Restore controller device state" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Fix USBGuard configuration" "RestoreControllerDeviceState invalid \"${USBGUARD_RESTORE_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: RestoreControllerDeviceState not found"
Display --indent 6 --text "- Restore controller device state" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for controllers connected before daemon starts (PresentControllerPolicy)"
USBGUARD_CONTROLLER_POLICY=$(${AWKBINARY} -F '=' -v OPT="PresentControllerPolicy" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_CONTROLLER_POLICY}" ]; then
LogText "Result: PresentControllerPolicy = ${USBGUARD_CONTROLLER_POLICY}"
case "${USBGUARD_CONTROLLER_POLICY}" in
"allow" | "keep")
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "${USBGUARD_CONTROLLER_POLICY}" --color YELLOW
LogText " Consider changing PresentControllerPolicy to \"apply-policy\", \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Consider hardening USBGuard configuration" "PresentControllerPolicy (${USBGUARD_CONTROLLER_POLICY} --> (apply-policy|block|reject)"
AddHP 0 1
;;
"apply-policy" | "block" | "reject")
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "${USBGUARD_CONTROLLER_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for PresentControllerPolicy"
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Fix USBGuard configuration" "PresentControllerPolicy invalid \"${USBGUARD_CONTROLLER_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: PresentControllerPolicy not found"
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for devices connected before daemon starts (PresentDevicePolicy)"
USBGUARD_DEVICE_POLICY=$(${AWKBINARY} -F '=' -v OPT="PresentDevicePolicy" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_DEVICE_POLICY}" ]; then
LogText "Result: PresentDevicePolicy = ${USBGUARD_DEVICE_POLICY}"
case "${USBGUARD_DEVICE_POLICY}" in
"allow" | "keep")
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "${USBGUARD_DEVICE_POLICY}" --color YELLOW
LogText " Consider changing PresentDevicePolicy to \"apply-policy\", \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Consider hardening USBGuard configuration" "PresentDevicePolicy (${USBGUARD_DEVICE_POLICY} --> (apply-policy|block|reject)"
AddHP 0 1
;;
"apply-policy" | "block" | "reject")
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "${USBGUARD_DEVICE_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for PresentDevicePolicy"
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Fix USBGuard configuration" "PresentDevicePolicy invalid \"${USBGUARD_DEVICE_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: PresentDevicePolicy not found"
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for devices inserted after daemon starts (InsertedDevicePolicy)"
USBGUARD_INSERTED_POLICY=$(${AWKBINARY} -F '=' -v OPT="InsertedDevicePolicy" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_INSERTED_POLICY}" ]; then
LogText "Result: InsertedDevicePolicy = ${USBGUARD_INSERTED_POLICY}"
case "${USBGUARD_INSERTED_POLICY}" in
"allow" | "keep")
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "${USBGUARD_INSERTED_POLICY}" --color YELLOW
LogText " Consider changing InsertedDevicePolicy to \"apply-policy\", \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Consider hardening USBGuard configuration" "InsertedDevicePolicy (${USBGUARD_INSERTED_POLICY} --> (apply-policy|block|reject)"
AddHP 0 1
;;
"apply-policy" | "block" | "reject")
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "${USBGUARD_INSERTED_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for InsertedDevicePolicy"
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Fix USBGuard configuration" "InsertedDevicePolicy invalid \"${USBGUARD_INSERTED_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: InsertedDevicePolicy not found"
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for devices not in RuleFile (ImplicitPolicyTarget)"
USBGUARD_DEFAULT_POLICY=$(${AWKBINARY} -F '=' -v OPT="ImplicitPolicyTarget" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_DEFAULT_POLICY}" ]; then
LogText "Result: ImplicitPolicyTarget = ${USBGUARD_DEFAULT_POLICY}"
case "${USBGUARD_DEFAULT_POLICY}" in
"allow")
Display --indent 6 --text "- Rule for devices not in RuleFile" --result "${USBGUARD_DEFAULT_POLICY}" --color YELLOW
LogText " Consider changing ImplicitPolicyTarget to \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Consider hardening USBGuard configuration" "ImplicitPolicyTarget (${USBGUARD_DEFAULT_POLICY} --> (block|reject)"
AddHP 0 1
;;
"block"|"reject")
Display --indent 6 --text "- Rule for devices not in RuleFile" --result "${USBGUARD_DEFAULT_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for ImplicitPolicyTarget"
Display --indent 6 --text "- Rule for devices not in RuleFile" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion ${TEST_NO} "Fix USBGuard configuration" "ImplicitPolicyTarget invalid \"${USBGUARD_DEFAULT_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: ImplicitPolicyTarget not found"
Display --indent 4 --text "- Rule for devices not in RuleFile" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking RuleFile"
USBGUARD_RULES=$(${AWKBINARY} -F '=' -v OPT="RuleFile" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_RULES}" ] && [ -f "${USBGUARD_RULES}" ]; then
LogText "Result: RuleFile found (${USBGUARD_RULES})"
Display --indent 4 --text "- RuleFile" --result "${STATUS_FOUND}" --color GREEN
AddHP 1 1
USBGUARD_RULES_ALLOW=$(${EGREPBINARY} -c "^allow" ${USBGUARD_RULES})
Display --indent 6 --text "- Controllers & Devices allow" --result "${USBGUARD_RULES_ALLOW}" --color WHITE
USBGUARD_RULES_BLOCK=$(${EGREPBINARY} -c "^block" ${USBGUARD_RULES})
Display --indent 6 --text "- Controllers & Devices block" --result "${USBGUARD_RULES_BLOCK}" --color WHITE
USBGUARD_RULES_REJECT=$(${EGREPBINARY} -c "^reject" ${USBGUARD_RULES})
Display --indent 6 --text "- Controllers & Devices reject" --result "${USBGUARD_RULES_REJECT}" --color WHITE
else
LogText "Result: RuleFile not found (\"man usbguard\" for instructions to install initial policies)"
Display --indent 4 --text "- RuleFile" --result "${STATUS_NOT_FOUND}" --color RED
# To-Be-Added: assign TEST_NO, create documentation, and enable the suggestion
#ReportSuggestion ${TEST_NO} "Install USBGuard RuleFile" "\"man usbguard\" for instructions to install initial policies"
AddHP 0 1
fi
else
Display --indent 4 --text "- Configuration" --result "${STATUS_NOT_FOUND}" --color WHITE
LogText "Result: Configuration not found"
# To-Be-Added: assign TEST_NO, create documentation, and enable the suggestion
#ReportSuggestion ${TEST_NO} "USBGuard configuration file not found, consider reinstalling"
AddHP 0 7
fi
else
LogText "Result: USBGuard not found"
Display --indent 2 --text "- Checking USBGuard" --result "${STATUS_NOT_FOUND}" --color WHITE
# To-Be-Added: assign TEST_NO, create documentation, and enable the suggestion
#ReportSuggestion ${TEST_NO} "Install USBGuard to allow for fine-grained control of USB authorization"
AddHP 0 8
fi
fi
#
#################################################################################
#
WaitForKeyPress
#
#================================================================================
# Lynis - Security Auditing and System Hardening for Linux and UNIX - https://cisofy.com
|