Side-channel processor vulnerabilities CVE-2017-5715, CVE-2017-5753, and CVE-2017-5754

F5 Product Development has assigned IDs 698651, 701445, 701447, 704490, and 704483 (BIG-IP); 702233, 702236, and 702237 (BIG-IQ); 702353, 702354, and 702355 (Enterprise Manager); 702355, 702377, and 702378 (iWorkflow); CPF-24782, CPF-24783, and CPF-24784 (Traffix); LRS-65859, LRS-65860, and LRS-65861 (LineRate) to this vulnerability. Additionally, BIG-IP iHealth may list Heuristic H91229003 on the Diagnostics >Identified>Medium page.

To determine if your product and version have been evaluated for this vulnerability, refer to the Applies to (see versions) box. 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	Branch	Versions known to be vulnerable	Fixes introduced in	Severity	CVSSv3 score1	Vulnerable component or feature
BIG-IP (LTM, AAM, AFM, Analytics, APM, ASM, DNS, Edge Gateway, GTM, Link Controller, PEM, WebAccelerator, WebSafe)	15.x	None	15.0.0	Medium (CVE-2017-5715)
Medium (CVE-2017-5753)
Medium (CVE-2017-5754)	6.4 CVE-2017-5715
5.3 CVE-2017-5753
6.4 CVE-2017-5754	CPU, BIOS, and kernel
14.x	None	14.0.02
13.x	13.0.0 - 13.1.0	13.1.0.42
13.0.12
12.x	12.1.0 - 12.1.3	12.1.3.32
11.x	11.6.1 - 11.6.3
11.5.1 - 11.5.5
11.2.1	11.6.3.12
11.5.62
Enterprise Manager	3.x	3.1.1	None	Medium (CVE-2017-5715)
Medium (CVE-2017-5753)
Medium (CVE-2017-5754)	6.4 CVE-2017-5715
5.3 CVE-2017-5753
6.4 CVE-2017-5754	CPU, BIOS, and kernel
BIG-IQ (Cloud, Device, Security, ADC)	4.x	4.5.0	None	Medium (CVE-2017-5715)
Medium (CVE-2017-5753)
Medium (CVE-2017-5754)	6.4 CVE-2017-5715
5.3 CVE-2017-5753
6.4 CVE-2017-5754	CPU, BIOS, and kernel
BIG-IQ Centralized Management	6.x	6.0.0	6.0.12	Medium (CVE-2017-5715)
Medium (CVE-2017-5753)
Medium (CVE-2017-5754)	6.4 CVE-2017-5715
5.3 CVE-2017-5753
6.4 CVE-2017-5754	CPU, BIOS, and kernel
5.x	5.0.0 - 5.4.0	None
4.x	4.6.0	None
BIG-IQ Cloud and Orchestration	1.x	1.0.0	None	Medium (CVE-2017-5715)
Medium (CVE-2017-5753)
Medium (CVE-2017-5754)	6.4 CVE-2017-5715
5.3 CVE-2017-5753
6.4 CVE-2017-5754	CPU, BIOS, and kernel
F5 iWorkflow	2.x	2.3.0
2.2.0
2.1.0
2.0.1 - 2.0.2	None	Medium (CVE-2017-5715)
Medium (CVE-2017-5753)
Medium (CVE-2017-5754)	6.4 CVE-2017-5715
5.3 CVE-2017-5753
6.4 CVE-2017-5754	CPU, BIOS, and kernel
LineRate	2.x	2.6.0	None	Medium	**	CPU, BIOS, and kernel
Traffix SDC	5.x	5.0.0 - 5.1.0	Security bulletin build 93 (5.1.0)
Security bulletin build 32 (5.0.0)	Medium (CVE-2017-5715)
High (CVE-2017-5753)
High (CVE-2017-5754)	6.7 (CVE-2017-5715)
8.2 (CVE-2017-5753)
7.9 (CVE-2017-5754)	CPU, BIOS, and kernel
4.x	4.0.0 - 4.4.0	Security bulletin build 14 (4.4.0)

1The CVSSv3 score link takes you to a resource outside of AskF5, and it is possible that the document may be removed without our knowledge.

2Notes about fixes for CVE-2017-5753 (Spectre-PHT) and CVE-2017-5754 (Meltdown-US):

Important: F5 does not plan to release an official fix for CVE-2017-5715 (Spectre-BTB) that is based on Intel’s microcode updates. The rationale for this decision is based on significant performance degradation when enabling Intel’s microcode fixes in our platforms. During testing of the microcode fix, F5 has observed from 10 percent to more than 50 percent performance degradation for many workloads.

Important: Only CVE-2017-5754 (Meltdown-US) is fixed in BIG-IQ.

• Performance impact:
  • CVE-2017-5753 (Spectre-PHT)

F5 does not anticipate a performance impact as a result of the fix for CVE-2017-5753 Spectre-PHT.

* CVE-2017-5754 (Meltdown-US)

In most scenarios, the fix for Meltdown-US has a negligible performance impact. F5 recommends testing the performance impact before deploying the fix in a production environment, or testing the fix during a maintenance window with consideration to the possible impact on your specific environment. If you encounter unacceptable performance issues in testing and choose to disable the Meltdown-US fix, you can do so by typing the following command:

tmsh modify sys db kernel.pti value disable

Note: This database variable change is applied without requirement for a reboot.

Important: If you choose to disable the Meltdown-US fix, the system will be vulnerable to the Meltdown-US vulnerability. However, in order to take advantage of this vulnerability, the attacker must already possess the ability to run arbitrary code on the system. For non-vCMP systems, good access controls and keeping your system up-to-date with security fixes will mitigate this risk. For vCMP systems with multiple tenants, F5 recommends that you leave the Meltdown-US fix enabled.

• Virtual F5 products/vCMP guests:

The Meltdown-US and Spectre-PHT fixes block the ability for those exploits to be executed on the patched OS. If the exploit allows cross-VM boundary information leaks, then a fixed VM is still vulnerable to attacks from a non-fixed VM or the host. Therefore, it is important to apply fixes to both guest VMs and the host that runs them.

• Known issues:

Due to a known issue with the Meltdown-US fix on BIG-IP platforms equipped with an AMD processor, the system may spontaneously reboot. Refer to the table in the Impact section for information about which BIG-IP platforms have an AMD processor. F5 Product Development has assigned ID 719711 to this issue. To work around the issue, you can disable the Meltdown-US fix (BIG-IP platforms with an AMD processor are not vulnerable to Meltdown-US per the table in the** Impact** section). To do so, perform the following procedure:

Note: Performing the procedure to disable kernel page-table isolation does not disable the Spectre-PHT fix.

1. Log in to the BIG-IP command line.
2. Disable the kernel page-table isolation (PTI) database key by typing the following command: 

tmsh modify sys db kernel.pti value disable

3. Reboot the BIG-IP system by typing the following command: 

reboot

Note: A reboot is required for this workaround.

Important: This command will interrupt traffic while the BIG-IP system either fails over to a peer system or completes the reboot process.

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 theFixes introduced in 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.

Mitigation

BIG-IP

The only roles on a BIG-IP system that can exploit these vulnerabilities are the Administrator, Resource Administrator, Manager, and iRules Manager roles. To mitigate against all three vulnerabilities, ensure that you limit access to these roles to only trusted employees.

To mitigate the Spectre-BTB vulnerability in multi-tenancy vCMP configurations, ensure that all guests are set to at least two Cores Per Guest.

Traffix SDC

Fixes for CVE-2017-5715, CVE-2017-5753, and CVE-2017-5754 are available from F5 via the following security bulletins for Traffix SDC 5.1.0, 5.0.0, and 4.4.0:

• 5.1.0 - security bulletin build 93
• 5.0.0 - security bulletin build 32
• 4.4.0 - security bulletin build 14

For more information, contact your Traffix SDC Technical Support representative.

• <https://googleprojectzero.blogspot.ca/2018/01/reading-privileged-memory-with-side.html&gt;

Note: This link takes you to a resource outside of AskF5. The third party could remove the document without our knowledge.

• <https://meltdownattack.com/&gt;

Note: This link takes you to a resource outside of AskF5. The third party could remove the document without our knowledge.

• K51812227: Understanding Security Advisory versioning
• K9970: Subscribing to email notifications regarding F5 products
• K9957: Creating a custom RSS feed to view new and updated documents
• K4602: Overview of the F5 security vulnerability response policy
• K4918: Overview of the F5 critical issue hotfix policy
• K9502: BIG-IP hotfix and point release matrix