BIND vulnerability CVE-2016-2776

2016-09-27T21:51:00
ID F5:K18829561
Type f5
Reporter f5
Modified 2018-02-06T01:01:00

Description

F5 Product Development has assigned ID 616864 (BIG-IP), ID 617867 (BIG-IQ and iWorkflow), and ID 617869 (Enterprise Manager) to this vulnerability. Additionally, BIG-IP iHealth may list Heuristic H618448 on the Diagnostics > Identified > High screen.

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 - 12.1.1
11.4.0 - 11.6.1
11.2.1
10.2.1 - 10.2.4| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP AAM| 12.0.0 - 12.1.1
11.4.0 - 11.6.1| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP AFM| 12.0.0 - 12.1.1
11.4.0 - 11.6.1| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP Analytics| 12.0.0 - 12.1.1
11.4.0 - 11.6.1
11.2.1| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP APM| 12.0.0 - 12.1.1
11.4.0 - 11.6.1
11.2.1
10.2.1 - 10.2.4| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP ASM| 12.0.0 - 12.1.1
11.4.0 - 11.6.1
11.2.1
10.2.1 - 10.2.4| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP DNS| 12.0.0 - 12.1.1| 13.0.0
12.1.2| High| BIND
BIG-IP Edge Gateway| 11.2.1
10.2.1 - 10.2.4| None| High| BIND
BIG-IP GTM| 11.4.0 - 11.6.1
11.2.1
10.2.1 - 10.2.4| 11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP Link Controller| 12.0.0 - 12.1.1
11.4.0 - 11.6.1
11.2.1
10.2.1 - 10.2.4| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP PEM| 12.0.0 - 12.1.1
11.4.0 - 11.6.1| 13.0.0
12.1.2
11.6.1 HF2
11.5.4 HF4| High| BIND
BIG-IP PSM| 11.4.0 - 11.4.1
10.2.1 - 10.2.4| None| High| BIND
BIG-IP WebAccelerator| 11.2.1
10.2.1 - 10.2.4| None| High| BIND
BIG-IP WOM| 11.2.1
10.2.1 - 10.2.4| None| High| BIND
BIG-IP WebSafe| 12.0.0 - 12.1.1
11.6.0 - 11.6.1| 13.0.0
12.1.2
11.6.1 HF2| High

| BIND
ARX| None| 6.2.0 - 6.4.0| Not vulnerable| None
Enterprise Manager| 3.1.1| None| Low| BIND
FirePass| None| 7.0.0| Not vulnerable| None
BIG-IQ Cloud| 4.0.0 - 4.5.0| None| Low| BIND
BIG-IQ Device| 4.2.0 - 4.5.0| None| Low| BIND
BIG-IQ Security| 4.0.0 - 4.5.0| None| Low| BIND
BIG-IQ ADC| 4.5.0| None| Low| BIND
BIG-IQ Centralized Management| 5.1.0
4.6.0| None| Low| BIND
BIG-IQ Cloud and Orchestration| 1.0.0| None| Low| BIND
F5 iWorkflow| 2.0.0| None| Low| BIND
LineRate| None| 2.5.0 - 2.6.1| Not vulnerable| None
Traffix SDC| None| 5.0.0
4.0.0 - 4.4.0| Not vulnerable| None

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.

To determine the necessary upgrade path for your BIG-IQ system, you should understand the BIG-IQ product offering name changes. For more information, refer to K21232150: Considerations for upgrading BIG-IQ or F5 iWorkflow systems.

Mitigation

BIG-IP

To mitigate this vulnerability, you can use the DNS Caching and DNS Express features instead of BIND. In addition, to mitigate the issue on the management IP address, restrict access to that IP address to trusted hosts only.

To mitigate the issue on the self IP address, do not allow port 53 on the self IP address. If your self IP address is configured to use the default allow, you can remove that port from the list of the default allowed services.

Ensuring that TCP/UDP port 53 is not allowed as a default service (allow-service default)

  1. Log in to the Traffic Management Shell (tmsh) by typing the following command:

tmsh

  1. List the default services allowed by the allow-service default setting, by typing the following command:

list net self-allow

The command output appears similar to the following example:

net self-allow {
defaults {
ospf:any
tcp:domain
tcp:f5-iquery
tcp:https
tcp:snmp
tcp:ssh
udp:520
udp:cap
udp:domain
udp:f5-iquery
udp:snmp
}
}

  1. If TCP port 53 (tcp:53 or tcp:domain) or UDP port 53 (udp:53 or udp:domain) are listed as a default allowed port, you should delete the entries by typing the following command:

modify net self-allow defaults delete { tcp:domain udp:domain }

  1. Save the configuration by typing the following command:

save sys config

Disabling the Use BIND Server on BIG-IP option on the DNS profile

To mitigate the issue on the DNS profile, you can disable the Use BIND Server on BIG-IP option by performing the following procedure:

  1. Log in to the Configuration utility.
  2. Navigate to DNS > Delivery > Profiles > DNS or Local Traffic > Profiles > Services > DNS.
  3. Select the applicable DNS profile.
  4. From the Use BIND Server on BIG-IP option, select Disabled.
  5. Click Finished.

Important: Disabling the BIND server can impact DNS configurations that use BIND as a fallback method (return to DNS) for resolution.

BIG-IP GTM/Link Controller

Verifying whether you have configured any listener addresses to share a self IP (BIG-IP GTM/Link Controller)

Listener addresses that share a self IP address will expose the system to this vulnerability. To verify whether you have configured a listener address to share a self IP, run the following commands:

  • tmsh list /net self address
  • tmsh list /gtm listener address

If you have configured a listener address to share a self IP, you should reconfigure the address to use a unique IP address.

Choosing a load balancing method other than Return to DNS for the GTM pool (BIG-IP GTM)

Important: If DNS Express is not configured, BIG-IP GTM or Link Controller systems will respond to A, AAAA, and CNAME type DNS record queries only. Queries for other types of records, such as NS or MX, will fail.

To mitigate the issue on the GTM pool, you can use a load balancing method other than Return to DNS by performing the following procedure:

  1. Log in to the Configuration utility.
  2. Navigate to DNS > GSLB > Pools.
  3. From the Pool List menu, select the applicable name.
  4. Click the Members tab.
  5. Choose a load balancing method other than Return to DNS.
  6. Click Update.

BIG-IQ, Enterprise Manager, or iWorkflow systems

To mitigate this vulnerability for the BIG-IQ system, the Enterprise Manager system, or the iWorkflow system, you should not configure any of these systems to function as a DNS server.

Impact of action: Performing the suggested mitigation should not have a negative impact on your system.