F5 Products: CVSS (Max): 7.8

May 1, 2024

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AUSCERT External Security Bulletin Redistribution

ESB-2024.2758
K000139430 : Linux kernel vulnerability CVE-2024-1086
1 May 2024

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AusCERT Security Bulletin Summary
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Product: F5OS-A
F5OS-C
Traffix SDC
Publisher: F5 Networks
Operating System: Linux
Resolution: Mitigation
CVE Names: CVE-2024-1086

Original Bulletin:
https://my.f5.com/manage/s/article/K000139430

Comment: CVSS (Max): 7.8 CVE-2024-1086 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVSS Source: F5 Networks
Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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K000139430: Linux kernel vulnerability CVE-2024-1086

Published Date: May 1, 2024
Updated Date: May 1, 2024

Security Advisory Description

A use-after-free vulnerability in the Linux kernel’s netfilter: nf_tables
component can be exploited to achieve local privilege escalation. The
nft_verdict_init() function allows positive values as drop error within the
hook verdict, and hence the nf_hook_slow() function can cause a double free
vulnerability when NF_DROP is issued with a drop error which resembles
NF_ACCEPT. We recommend upgrading past commit
f342de4e2f33e0e39165d8639387aa6c19dff660. (CVE-2024-1086)

Impact

When user namespaces are enabled and your system is using the Netfilter, a
local attacker with user access may be able to exploit this flaw leading to
privilege escalation.

Security Advisory Status

F5 Product Development has assigned ID 1577049 (F5OS) to this vulnerability.

To determine if your product and version have been evaluated for this
vulnerability, refer to the Evaluated products 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, point releases, or
hotfixes that address the vulnerability, refer to the following tables. You can
also use iHealth to diagnose a vulnerability for BIG-IP and BIG-IQ systems. For
more information about using iHealth, refer to K27404821: Using F5 iHealth to
diagnose vulnerabilities. For more information about security advisory
versioning, refer to K51812227: Understanding security advisory versioning.

In this section

o BIG-IP Next
o BIG-IP and BIG-IQ
o F5 Distributed Cloud Services
o F5OS
o NGINX
o Other products

BIG-IP Next

Note: After a fix is introduced for a given minor branch, that fix applies to
all subsequent maintenance and point releases for that branch, and no
additional fixes for that branch will be listed in the table. For example, when
a fix is introduced in 20.0.2, the fix also applies to 20.0.3, and all later
20.1.x releases. For more information, refer to K51812227: Understanding
security advisory versioning.

^1F5 evaluates only software versions that have not yet reached the End of
Technical Support (EoTS) phase of their lifecycle. For more information, refer
to the Security hotfixes section of K4602: Overview of the F5 security
vulnerability response policy.

BIG-IP and BIG-IQ

Note: After a fix is introduced for a given minor branch, that fix applies to
all subsequent maintenance and point releases for that branch, and no
additional fixes for that branch will be listed in the table. For example, when
a fix is introduced in 16.1.2.1, the fix also applies to 16.1.2.2, and all
later 16.1.x releases (16.1.3.x, 16.1.4.x). For more information, refer to
K51812227: Understanding security advisory versioning.

F5 Distributed Cloud Services

^1The specified services contain the affected code. However, F5 identifies the
vulnerability status as Not vulnerable because the attacker cannot exploit the
code in default, standard, or recommended configurations.

F5OS

^2The CVSSv3 score link takes you to a resource outside of MyF5, and the
content may be removed without our knowledge.

NGINX

Other products

Security Advisory Recommended Actions

If you are running a version listed in the Versions known to be vulnerable
column, you can eliminate this vulnerability by installing a version listed in
the Fixes introduced in column. If the Fixes introduced in column does not list
a version for your branch, then no update candidate currently exists for that
branch and F5 recommends that you upgrade to a version with the fix (refer to
the tables).

If the Fixes introduced in column lists a version prior to the one you are
running, in the same branch, then your version should have the fix.

Mitigation

As this attack is conducted by legitimate, authenticated users, there is no
viable mitigation that can restrict or limit user access to the F5OS-A or
F5OS-C system. The only mitigation is to remove access for users who are not
completely trusted.

Additionally, you should permit management access to the F5OS CLIs only over a
secure network and restrict access to only trusted users. To restrict network
access to F5OS Management, refer to the following F5 Cloud Docs guides:

F5OS-A

o The Allow List for F5OS Management chapter of the F5 rSeries Planning Guide

F5OS-C

o The Allow List for F5OS Management chapter of the Planning for VELOS Guide

Related Content

o K41942608: Overview of MyF5 security advisory articles
o K12201527: Overview of Quarterly Security Notifications
o K51812227: Understanding security advisory versioning
o K4602: Overview of the F5 security vulnerability response policy
o K4918: Overview of the F5 critical issue hotfix policy
o K39757430: F5 product and services lifecycle policy index
o K000090258: Download F5 products from MyF5
o K9970: Subscribing to email notifications regarding F5 products
o K9957: Creating a custom RSS feed to view new and updated documents
o K000135931: Contact F5 Support

AI Recommended Content

o K12201527 : Overview of Quarterly Security Notifications
o K4309 : F5 hardware product lifecycle support policy
o K000135931 : Contact F5 Support
o K7727 : License activation may be required before a software upgrade for
BIG-IP

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The University of Queensland
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