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IBM3D1FD9B5927004B8B7B1CB77FE467A67DED4E5A078A791448C81D1500BA2A09E
HistoryOct 28, 2020 - 1:21 p.m.

Security Bulletin: Publicly disclosed vulnerabilities from Kernel affect IBM Netezza Host Management

2020-10-2813:21:38
www.ibm.com
13

6.4 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

6.9 Medium

CVSS2

Access Vector

LOCAL

Access Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:L/AC:M/Au:N/C:C/I:C/A:C

Summary

Kernel is used by IBM Netezza Host Management. This bulletin provides mitigation for the reported CVEs.

Vulnerability Details

CVEID:CVE-2019-15214
**DESCRIPTION:**Linux Kernel could allow a physical attacker to execute arbitrary code on the system, caused by a use-after-free flaw in the sound subsystem. By performing card disconnection actions, an attacker could exploit this vulnerability to execute arbitrary code or cause a denial of service on the system.
CVSS Base score: 6.8
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/165535 for the current score.
CVSS Vector: (CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID:CVE-2019-15217
**DESCRIPTION:**Linux Kernel is vulnerable to a denial of service, caused by a NULL pointer dereference in the yurex.c driver. By using a specially-crafted USB device, a physical attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 4.6
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/165538 for the current score.
CVSS Vector: (CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2019-15218
**DESCRIPTION:**Linux Kernel is vulnerable to a denial of service, caused by a NULL pointer dereference in the smsusb.c driver. By using a specially-crafted USB device, a physical attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 4.6
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/165539 for the current score.
CVSS Vector: (CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2019-15219
**DESCRIPTION:**Linux Kernel is vulnerable to a denial of service, caused by a NULL pointer dereference in the sisusb.c driver. By using a specially-crafted USB device, a physical attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 4.6
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/165540 for the current score.
CVSS Vector: (CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2019-15291
**DESCRIPTION:**Linux Kernel is vulnerable to a denial of service, caused by a NULL pointer dereference in the flexcop_usb_probe function in the flexcop-usb.c driver. By using a specially-crafted USB device, a physical attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 4.6
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/165548 for the current score.
CVSS Vector: (CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

Affected Product(s) Version(s)
IBM Netezza Host Management All IBM Netezza Host Management starting 5.4.9.0

Remediation/Fixes

None

Workarounds and Mitigations

Mitigation of the reported CVEs : CVE-2019-15214, CVE-2019-15217, CVE-2019-15218, CVE-2019-15219, CVE-2019-15291 blocklisting kernel modules snd, zr364xx, smsusb, sisusbvga, b2c2-flexcop-usb to prevent them from loading automatically on PureData System for Analytics N200x and N3001 is as follows:

1. Change to user nz:
[root@nzhost1 ~]# su – nz

2. Check to see if Call Home is enabled:
[nz@nzhost1 ~]$ nzcallhome -status
If enabled, disable it:
[nz@nzhost1 ~]$ nzcallhome –off ** Note:** Ensure that nzcallhome returns status as disabled. If there are errors in the callHome.txt configuration file, errors are listed in the output, and call-Home is disabled.

3. Check the state of the Netezza system:
[nz@nzhost1 ~]$ nzstate

4. If the system state is online, stop the system using the command:
[nz@nzhost1 ~]$ nzstop

5. Wait for the system to stop, using the command:
[nz@nzhos1t ~]$ nzstate
System state is ‘Stopped’.

6. Exit from the nz session to return to user root:
[nz@nzhost1 ~]$ exit

7. Logged into the active host as root, type the following commands to stop the heartbeat processes:
[root@nzhost1 ~]# ssh ha2 /sbin/service heartbeat stop
[root@nzhost1 ~]# /sbin/service heartbeat stop

8. Run below commands as a root user to disable heartbeat from startup:
[root@nzhost1 ~]# ssh ha2 /sbin/chkconfig heartbeat off
[root@nzhost1 ~]# /sbin/chkconfig heartbeat off

9. Type the following commands to stop the DRBD processes:
[root@nzhost1 ~]# ssh ha2 /sbin/service drbd stop
[root@nzhost1 ~]#** /sbin/service drbd stop**

10. Run below commands as a root user to disable drbd from startup:
[root@nzhost1 ~]# ssh ha2 /sbin/chkconfig drbd off
[root@nzhost1 ~]# /sbin/chkconfig drbd off

Execute below steps using “root” user on both ha1/ha2 hosts

Step 1: Check if kernel modules are snd, zr364xx, smsusb, sisusbvga, b2c2-flexcop-usb loaded in the hosts

lsmod | grep snd lsmod | grep zr364xx lsmod | grep smsusb lsmod | grep sisusbvga lsmod | grep b2c2_flexcop_usb

example:
[root@ nzhost1 ~]# lsmod | grep snd
snd 74199 0
soundcore 7990 1 snd
[root@ nzhost1 ~]# lsmod | grep zr364xx
zr364xx 20096 0
videodev 76188 1 zr364xx
videobuf_vmalloc 5295 1 zr364xx
videobuf_core 20302 2 zr364xx,videobuf_vmalloc
[root@ nzhost1 ~]# lsmod | grep smsusb
smsusb 8924 0
smsmdtv 30790 1 smsusb
[root@ nzhost1 ~]# lsmod | grep sisusbvga
sisusbvga 51565 0
[root@ nzhost1 ~]# lsmod | grep b2c2_flexcop_usb
b2c2_flexcop_usb 5306 0
b2c2_flexcop 28746 1 b2c2_flexcop_usb

Note: No output onStep 1for any module indicates, that module is not loaded hence skipStep 2for that module, and proceed withStep 3

Step 2: Unload kernel modules are snd, zr364xx, smsusb, sisusbvga, b2c2-flexcop-usb if they are loaded

modprobe -rv snd modprobe -rv zr364xx modprobe -rv smsusb modprobe -rv sisusbvga modprobe -rv b2c2-flexcop-usb

example:
[root@nzhost1 ~]# modprobe -rv snd
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/sound/core/snd.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/sound/soundcore.ko
[root@nzhost1 ~]# modprobe -rv zr364xx
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/video/zr364xx.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/video/videodev.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/video/v4l2-compat-ioctl32.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/video/videobuf-vmalloc.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/video/videobuf-core.ko
[root@nzhost1 ~]# modprobe -rv smsusb
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/siano/smsusb.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/siano/smsmdtv.ko
[root@nzhost1 ~]# modprobe -rv sisusbvga
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/usb/misc/sisusbvga/sisusbvga.ko
[root@nzhost1 ~]# modprobe -rv b2c2-flexcop-usb
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/b2c2/b2c2-flexcop-usb.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/b2c2/b2c2-flexcop.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/dvb-core/dvb-core.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/frontends/cx24123.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/frontends/cx24113.ko
rmmod /lib/modules/2.6.32-754.35.1.el6.x86_64/kernel/drivers/media/dvb/frontends/s5h1420.ko

Kernel modules and their dependent modules will be unloaded in the reverse order that they are loaded, given that no processes depend on any of the modules being unloaded.

Step 3: To prevent modules from being loaded directly you add the blocklist line to a configuration file specific to the system configuration.

echo “blocklist snd” >> /etc/modprobe.d/local-blocklist.conf echo “blocklist zr364xx” >> /etc/modprobe.d/local-blocklist.conf echo “blocklist smsusb” >> /etc/modprobe.d/local-blocklist.conf echo “blocklist sisusbvga” >> /etc/modprobe.d/local-blocklist.conf echo “blocklist b2c2-flexcop-usb” >> /etc/modprobe.d/local-blocklist.conf

example :
[root@nzhost1 ~]# echo “blocklist snd” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “blocklist zr364xx” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “blocklist smsusb” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “blocklist sisusbvga” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “blocklist b2c2-flexcop-usb” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep snd
blocklist snd
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep zr364xx
blocklist zr364xx
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep smsusb
blocklist smsusb
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep sisusbvga
blocklist sisusbvga
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep b2c2-flexcop-usb
blocklist b2c2-flexcop-usb

Step 4: Kernel modules can be loaded directly or loaded as a dependency from another module
To prevent installation as a dependency from another module follow below step:

echo “install snd /bin/false” >> /etc/modprobe.d/local-blocklist.conf echo “install zr364xx /bin/false” >> /etc/modprobe.d/local-blocklist.conf echo “install smsusb /bin/false” >> /etc/modprobe.d/local-blocklist.conf echo “install sisusbvga /bin/false” >> /etc/modprobe.d/local-blocklist.conf echo “install b2c2-flexcop-usb /bin/false” >> /etc/modprobe.d/local-blocklist.conf

example:
[root@nzhost1 ~]# echo “install snd /bin/false” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “install zr364xx /bin/false” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “install smsusb /bin/false” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “install sisusbvga /bin/false” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# echo “install b2c2-flexcop-usb /bin/false” >> /etc/modprobe.d/local-blocklist.conf
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep snd
blocklist snd
install snd /bin/false
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep zr364xx
blocklist zr364xx
install zr364xx /bin/false
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep smsusb
blocklist smsusb
install smsusb /bin/false
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep sisusbvga
blocklist sisusbvga
install sisusbvga /bin/false
[root@nzhost1 ~]# cat /etc/modprobe.d/local-blocklist.conf | grep b2c2-flexcop-usb
blocklist b2c2-flexcop-usb
install b2c2-flexcop-usb /bin/false

The install line simply causes /bin/false to be run instead of installing a module.

Step 5: Make a backup copy of your initramfs.

cp /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.$(date +%m-%d-%H%M%S).bak

Example:
[root@nzhost1 ~]# cp /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.$(date +%m-%d-%H%M%S).bak
[root@nzhost1 ~]# uname -r
2.6.32-754.35.1.el6.x86_64
[root@nzhost1 ~]# ll /boot/initramfs-2.6.32-754.35.1.el6.x86_64.img.10-28-041219.bak
-rw------- 1 root root 22387682 Oct 28 04:12 /boot/initramfs-2.6.32-754.35.1.el6.x86_64.img.10-28-041219.bak

Step 6: If the kernel module is part of the initramfs (boot configuration), rebuild your initial ramdisk image, omitting the module to be avoided

dracut --omit-drivers snd -f dracut --omit-drivers zr364xx -f dracut --omit-drivers smsusb -f dracut --omit-drivers sisusbvga -f dracut --omit-drivers b2c2-flexcop-usb -f

example:
[root@nzhost1 ~]# dracut --omit-drivers snd -f
[root@nzhost1 ~]# dracut --omit-drivers zr364xx -f
[root@nzhost1 ~]# dracut --omit-drivers smsusb -f
[root@nzhost1 ~]# dracut --omit-drivers sisusbvga -f
[root@nzhost1 ~]# dracut --omit-drivers b2c2-flexcop-usb -f
[root@nzhost1 ~]# lsinitrd /boot/initramfs-2.6.32-754.35.1.el6.x86_64.img | grep snd
[root@nzhost1 ~]# lsinitrd /boot/initramfs-2.6.32-754.35.1.el6.x86_64.img | grep zr364xx
[root@nzhost1 ~]# lsinitrd /boot/initramfs-2.6.32-754.35.1.el6.x86_64.img | grep smsusb
[root@nzhost1 ~]# lsinitrd /boot/initramfs-2.6.32-754.35.1.el6.x86_64.img | grep sisusbvga
[root@nzhost1 ~]# lsinitrd /boot/initramfs-2.6.32-754.35.1.el6.x86_64.img | grep b2c2-flexcop-usb

Step 7: Append module_name.blocklist to the kernel cmdline. We give it an invalid parameter of blocklist and set it to 1 as a way to preclude the kernel from loading it.

sed --follow-symlinks -i ‘/\skernel /vmlinuz/s/$/ snd.blocklist=1/’ /etc/grub.conf
sed --follow-symlinks -i '/\s
kernel /vmlinuz/s/$/ zr364xx.blocklist=1/’ /etc/grub.conf
sed --follow-symlinks -i ‘/\skernel /vmlinuz/s/$/ smsusb.blocklist=1/’ /etc/grub.conf
sed --follow-symlinks -i '/\s
kernel /vmlinuz/s/$/ sisusbvga.blocklist=1/’ /etc/grub.conf
sed --follow-symlinks -i ‘/\s*kernel /vmlinuz/s/$/ b2c2-flexcop-usb.blocklist=1/’ /etc/grub.conf

example :
[root@nzhost1 ~]# sed --follow-symlinks -i ‘/\skernel /vmlinuz/s/$/ snd.blocklist=1/’ /etc/grub.conf
[root@nzhost1 ~]# sed --follow-symlinks -i '/\s
kernel /vmlinuz/s/$/ zr364xx.blocklist=1/’ /etc/grub.conf
[root@nzhost1 ~]# sed --follow-symlinks -i ‘/\skernel /vmlinuz/s/$/ smsusb.blocklist=1/’ /etc/grub.conf
[root@nzhost1 ~]# sed --follow-symlinks -i '/\s
kernel /vmlinuz/s/$/ sisusbvga.blocklist=1/’ /etc/grub.conf
[root@nzhost1 ~]# sed --follow-symlinks -i ‘/\s*kernel /vmlinuz/s/$/ b2c2-flexcop-usb.blocklist=1/’ /etc/grub.conf

Step 8: blocklist the kernel module in kdump’s configuration file.

echo “blocklist snd” >> /etc/kdump.conf echo “blocklist zr364xx” >> /etc/kdump.conf echo “blocklist smsusb” >> /etc/kdump.conf echo “blocklist sisusbvga” >> /etc/kdump.conf echo “blocklist b2c2-flexcop-usb” >> /etc/kdump.conf

example:
[root@nzhost1 ~]# echo “blocklist snd” >> /etc/kdump.conf
[root@nzhost1 ~]# echo “blocklist zr364xx” >> /etc/kdump.conf
[root@nzhost1 ~]# echo “blocklist smsusb” >> /etc/kdump.conf
[root@nzhost1 ~]# echo “blocklist sisusbvga” >> /etc/kdump.conf
[root@nzhost1 ~]# echo “blocklist b2c2-flexcop-usb” >> /etc/kdump.conf
[root@nzhost1 ~]# cat /etc/kdump.conf | grep snd
blocklist snd
[root@nzhost1 ~]# cat /etc/kdump.conf | grep zr364xx
blocklist zr364xx
[root@nzhost1 ~]# cat /etc/kdump.conf | grep smsusb
blocklist zr364xx
[root@nzhost1 ~]# cat /etc/kdump.conf | grep sisusbvga
blocklist sisusbvga
[root@nzhost1 ~]# cat /etc/kdump.conf | grep b2c2-flexcop-usb
blocklist b2c2-flexcop-usb

Note: PerformStep 9if kexec-tools is installed and kdump is configured else continue withStep 10.
Perform below commands to check if kexec-tools is installed and Kdump is operational
[root@nzhost1 ~]# rpm -qa | grep kexec-tools
[root@nzhost1 ~]# service kdump status

Step 9: Restart the kdump service to pick up the changes to kdump’s initrd.

service kdump restart

example:
[root@nzhost1 ~]# service kdump restart
Stopping kdump: [ OK ]
Detected change(s) the following file(s):

/etc/kdump.conf
Rebuilding /boot/initrd-2.6.32-754.31.1.el6.x86_64kdump.img
Starting kdump: [ OK ]

Step 10: Reboot the system at a convenient time to have the changes take effect.
Make sure the secondary host is up by pinging or logging in before rebooting the primary host.

/sbin/shutdown -r now

example:
[root@nzhost1 ~]# /sbin/shutdown -r now
Make sure the primary server comes up and is reachable before performing Mitigation steps on the secondary server.

** After applying the mitigation:**

1. Start the services using following:
[root@nzhost1 ~]# service heartbeat start
[root@nzhost1 ~]#** ssh ha2 service heartbeat start**
[root@nzhost1 ~]# service drbd start
[root@nzhost1 ~]# ssh ha2 service drbd start

2. Check the stat of the system. Type:
[root@nzhost1 ~]# crm_mon -i5

Result: When the cluster manager comes up and is ready, status appears as follows.
Make sure that nzinit has started before you proceed. (This could take a few minutes.)
Node: nps61074 (e890696b-ab7b-42c0-9e91-4c1cdacbe3f9): online
Node: nps61068 (72043b2e-9217-4666-be6f-79923aef2958): online
Resource Group: nps
drbd_exphome_device(heartbeat:drbddisk): Started nps61074
drbd_nz_device(heartbeat:drbddisk): Started nps61074
exphome_filesystem(heartbeat::ocf:Filesystem): Started nps61074
nz_filesystem (heartbeat::ocf:Filesystem): Started nps61074
fabric_ip (heartbeat::ocf:IPaddr): Started nps61074
wall_ip (heartbeat::ocf:IPaddr): Started nps61074
nzinit (lsb:nzinit): Started nps61074
fencing_route_to_ha1(stonith:apcmaster): Started nps61074
fencing_route_to_ha2(stonith:apcmaster): Started nps61068

3. From host 1 (ha1), press Ctrl+C to break out of crm_mon.

4. Turn on heartbeat and DRBD using the chkconfig:
ssh ha2 /sbin/chkconfig drbd on ** /sbin/chkconfig drbd on** ** ssh ha2 /sbin/chkconfig heartbeat on** ** /sbin/chkconfig heartbeat on**

CPENameOperatorVersion
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API usage cases
  • Network scanning
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Ways of integration

Integrate Vulners API

6.4 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

6.9 Medium

CVSS2

Access Vector

LOCAL

Access Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:L/AC:M/Au:N/C:C/I:C/A:C

Related for 3D1FD9B5927004B8B7B1CB77FE467A67DED4E5A078A791448C81D1500BA2A09E