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AUSCERT External Security Bulletin Redistribution
ESB-2016.1966.2
sol19784568: TMM vulnerability CVE-2016-5023
24 August 2016
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AusCERT Security Bulletin Summary
---------------------------------
Product: F5 BIG-IP products
Publisher: F5 Networks
Operating System: Virtualisation
Network Appliance
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2016-5023
Original Bulletin:
https://support.f5.com/kb/en-us/solutions/public/k/19/sol19784568.html
Revision History: August 24 2016: Additional information added to Vulnerability Recommended Actions section
August 15 2016: Initial Release
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sol19784568: TMM vulnerability CVE-2016-5023
Security Advisory
Original Publication Date: 08/11/2016
Vulnerability Description
An unauthenticated remote attacker may be able to disrupt services on the
BIG-IP with maliciously crafted network traffic. This vulnerability affects
virtual servers associated with TCP profiles. The management interface is not
affected by this vulnerability. (CVE-2016-5023)
Impact
Traffic Management Microkernel (TMM) may restart and temporarily fail to
process traffic. Virtual servers configured with TCP profile are vulnerable to
this issue. Additionally, BIG-IP systems running 11.5.x and earlier that are
configured with TCP profile settings Slow Start disabled (enabled by default)
and Congestion Metrics Cache enabled (enabled by default) have a higher risk
of exposure.
Security Issue Status
F5 Product Development has assigned ID 572495 (BIG-IP) to this vulnerability.
To determine if your release is known to be vulnerable, the components or
features that are affected by the vulnerability, and for information about
releases or hotfixes that address the vulnerability, refer to the following
table:
Product Versions known to be vulnerable Versions known to be not vulnerable Severity Vulnerable component or feature
BIG-IP LTM 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.2.1 HF11 - HF15 11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
11.2.1 HF16
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP AAM 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
BIG-IP AFM 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
BIG-IP Analytics 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.2.1 HF11 - HF15 11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
11.2.1 HF16
11.2.1 - 11.2.1 HF10
BIG-IP APM 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.2.1 HF11 - HF15 11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
11.2.1 HF16
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP ASM 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.2.1 HF11 - HF15 11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
11.2.1 HF16
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP DNS 12.0.0 12.1.0 High Virtual servers with TCP profile
12.0.0 HF3
BIG-IP Edge Gateway 11.2.1 HF11 - HF15 11.2.1 HF16 High Virtual servers with TCP profile
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP GTM 11.6.0 HF5 - HF7 11.6.1 High Virtual servers with TCP profile
11.5.3 - 11.5.4 11.6.0 - 11.6.0 HF4
11.4.1 HF4 - HF10 11.5.4 HF2
11.2.1 HF11 - HF15 11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
11.2.1 HF16
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP Link Controller 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.2.1 HF11 - HF15 11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
11.2.1 HF16
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP PEM 12.0.0 12.1.0 High Virtual servers with TCP profile
11.6.0 HF5 - HF7 12.0.0 HF3
11.5.3 - 11.5.4 11.6.1
11.4.1 HF4 - HF10 11.6.0 - 11.6.0 HF4
11.5.4 HF2
11.5.0 - 11.5.2
11.4.0 - 11.4.1 HF3
BIG-IP PSM 11.4.1 HF4 - HF10 11.4.0 - 11.4.1 HF3 High Virtual servers with TCP profile
11.2.1 HF11 - HF15 11.2.1 HF16
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP WebAccelerator 11.2.1 HF11 - HF15 11.2.1 HF16 High Virtual servers with TCP profile
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
BIG-IP WOM 11.2.1 HF11 - HF15 11.2.1 HF16 High Virtual servers with TCP profile
11.2.1 - 11.2.1 HF10
10.2.1 - 10.2.4
ARX None 6.2.0 - 6.4.0 Not vulnerable None
Enterprise Manager None 3.1.1 Not vulnerable None
FirePass None 7.0.0 Not vulnerable None
BIG-IQ Cloud None 4.0.0 - 4.5.0 Not vulnerable None
BIG-IQ Device None 4.2.0 - 4.5.0 Not vulnerable None
BIG-IQ Security None 4.0.0 - 4.5.0 Not vulnerable None
BIG-IQ ADC None 4.5.0 Not vulnerable None
BIG-IQ Centralized Management None 5.0.0 Not vulnerable None
BIG-IQ Cloud and Orchestration None 1.0.0 Not vulnerable None
F5 iWorkflow None 2.0.0 Not vulnerable None
LineRate None 2.5.0 - 2.6.1 Not vulnerable None
F5 MobileSafe ** ** ** **
F5 WebSafe ** ** ** **
Traffix SDC None 5.0.0 Not vulnerable None
4.0.0 - 4.4.0
** Confirmation of vulnerability or non-vulnerability is not presently
available. F5 is still researching the issue for the products indicated, and
will update this article with the most current information as soon as it has
been confirmed. F5 Technical Support does not have any additional information
on this issue.
Vulnerability Recommended Actions
If you are running a version listed in the Versions known to be vulnerable
column, you can eliminate this vulnerability by upgrading to a version listed
in the Versions known to be not vulnerable column. If the table lists only an
older version than what you are currently running, or does not list a
non-vulnerable version, then no upgrade candidate currently exists.
BIG-IP 11.6.0 and later
To reduce the risk of exposure to this vulnerability, you must enable the
tm.tcpprogressive database variable, as well as enable both the Multipath TCP
and Rate Pace settings in the affected TCP profile. To do so, perform the
following procedure:
Note: Performing the following procedure only reduces the risk of exposure;
the procedures do not completely eliminate the vulnerability. To resolve this
vulnerability, F5 recommends that you upgrade to a version listed in the
Versions known to be not vulnerable column.
Impact of action: Modifying the database variable requires restarting TMM, and
will halt all traffic processing. You should perform this procedure during a
planned maintenance window. Depending on your application environment,
modifying these TCP settings may impact the performance of the associated
virtual server. Additionally, modifying the TCP profile of a virtual server
while it is processing traffic may have an adverse impact on the performance
of the affected virtual server. F5 recommends that you perform adequate
testing in your application environment, and implement the changes during an
appropriate maintenance period.
1. Log in to the Traffic Management Shell (tmsh) by typing the following
command:
tmsh
2. Enable the database variable tm.tcpprogressive by typing the following
command:
modify sys db tm.tcpprogressive value enable
3. Enable the Multipath TCP and Rate Pace settings for the affected TCP
profile by using the following command syntax:
modify ltm profile tcp <affected tcp profile name> mptcp enabled rate-pace
enabled
For example, you would type the following command to enable Multipath TCP and
Rate Pace settings for the mytcpprof profile:
modify ltm profile tcp mytcpprof mptcp enabled rate-pace enabled
4. Repeat the previous step for each of the affected TCP profiles.
5. Save the changes by typing the following command:
save sys config partitions all
6. Restart the tmm process by typing the following command:
restart /sys service tmm
BIG-IP 11.5.x
To reduce the risk of exposure to this vulnerability, you must enable both the
Multipath TCP and Rate Pace settings as well as set the Initial Congestion
Window Size setting to 1, and enable the Slow Start setting in the affected
TCP profile. To do so, perform the following procedure:
Note: Performing the following procedure only reduces the risk of exposure;
the procedures do not completely eliminate the vulnerability. To resolve this
vulnerability, F5 recommends that you upgrade to a version listed in the
Versions known to be not vulnerable column.
Impact of action: Depending on your application environment, modifying these
TCP settings may impact the performance of the associated virtual server.
Additionally, modifying the TCP profile of a virtual server while it is
processing traffic may have an adverse impact on the performance of the
affected virtual server. F5 recommends that you perform adequate testing in
your application environment, and implement the changes during an appropriate
maintenance period.
1. Log in to the Traffic Management Shell (tmsh) by typing the following
command:
tmsh
2. Enable the Multipath TCP and Rate Pace settings for the affected TCP
profile by using the following command syntax:
modify ltm profile tcp <affected tcp profile name> mptcp enabled rate-pace
enabled
For example, you would type the following command to enable Multipath TCP and
Rate Pace settings for the mytcpprof profile:
modify ltm profile tcp mytcpprof mptcp enabled rate-pace enabled
3. Set the Initial Congestion Window Size setting to 1, and enable the Slow
Start setting in the affected TCP profile by using the following command
syntax:
modify ltm profile tcp <affected tcp profile name> init-cwnd 1 slow-start
enabled
For example, you would type the following command to set these settings for
the mytcpprof profile:
modify ltm profile tcp mytcpprof init-cwnd 1 slow-start enabled
4. Repeat the previous step for each of the affected TCP profiles.
5. Save the changes by typing the following command:
save sys config partitions all
BIG-IP 11.3.0 through, and including, 11.4.1
To reduce the risk of exposure to this vulnerability, you must set the Initial
Congestion Window Size setting to 1, and enable the Slow Start setting in the
affected TCP profile. To do so, perform the following procedure:
Note: Performing the following procedure only reduces the risk of exposure;
the procedures do not completely eliminate the vulnerability. To resolve this
vulnerability, F5 recommends that you upgrade to a version listed in the
Versions known to be not vulnerable column.
Impact of action: Depending on your application environment, modifying these
TCP settings may impact the performance of the associated virtual server.
Additionally, modifying the TCP profile of a virtual server while it is
processing traffic may have an adverse impact on the performance of the
affected virtual server. F5 recommends that you perform adequate testing in
your application environment, and implement the changes during an appropriate
maintenance period.
1. Log in to the Traffic Management Shell (tmsh) by typing the following
command:
tmsh
2. Set the Initial Congestion Window Size setting to 1, and enable the Slow
Start setting in the affected TCP profile by using the following command
syntax:
modify ltm profile tcp <affected tcp profile name> init-cwnd 1 slow-start
enabled
For example, you would type the following command to set these settings for
the mytcpprof profile:
modify ltm profile tcp mytcpprof init-cwnd 1 slow-start enabled
3. Repeat the previous step for each of the affected TCP profiles.
4. Save the changes by typing the following command:
save sys config partitions all
BIG-IP 11.2.1 and earlier
To reduce the risk of exposure to this vulnerability for versions prior to
BIG-IP 11.3.0, you must enable the tm.tcpprogressive database variable as well
as set the Initial Congestion Window Size setting to 1, and enable the Slow
Start setting in the affected TCP profile. To do so, perform the following
procedure:
Note: Performing the following procedure only reduces the risk of exposure;
the procedures do not completely eliminate the vulnerability. To resolve this
vulnerability, F5 recommends that you upgrade to a version listed in the
Versions known to be not vulnerable column.
Impact of action: Modifying the database variable requires restarting TMM, and
will temporarily halt all traffic processing. You should perform this
procedure during a planned maintenance window. Depending on your application
environment, modifying these TCP profile settings may impact the performance
of the associated virtual server. Additionally, modifying the TCP profile of a
virtual server while it is processing traffic may have an adverse impact on
the performance of the affected virtual server. F5 recommends that you perform
adequate testing in your application environment, and implement the changes
during an appropriate maintenance period.
1. Log in to the tmsh utility by typing the following command:
tmsh
2. Enable the tm.tcpprogressive database variable by typing the following
command:
modify sys db tm.tcpprogressive value enable
3. Set the Initial Congestion Window Size setting to 1, and enable the Slow
Start setting in the affected TCP profile by using the following command
syntax:
modify ltm profile tcp <affected tcp profile name> init-cwnd 1 slow-start
enabled
For example, you would type the following command to set these settings for
the mytcpprof profile:
modify ltm profile tcp mytcpprof init-cwnd 1 slow-start enabled
4. Repeat the previous step for each of the affected TCP profiles.
Save the changes by typing the following command:
save sys config partitions all
5. Restart the tmm process by typing the following command:
restart /sys service tmm
Supplemental Information
SOL9970: Subscribing to email notifications regarding F5 products
SOL9957: Creating a custom RSS feed to view new and updated documents
SOL4602: Overview of the F5 security vulnerability response policy
SOL4918: Overview of the F5 critical issue hotfix policy
SOL167: Downloading software and firmware from F5
SOL13123: Managing BIG-IP product hotfixes (11.x - 12.x)
SOL10025: Managing BIG-IP product hotfixes (10.x)
SOL9502: BIG-IP hotfix matrix
SOL70025261: Overview of the TCP profile (12.x)
SOL13924148: Overview of the TCP profile (11.x)
SOL7559: Overview of the TCP profile (9.x - 10.x)
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