CVE-2018-5391: The Linux kernel, versions 3.9+, IP implementation is vulnerable to denial of service conditions with low rates of specially modified packets

Published Jul 30, 2018
·
Updated

A flaw named FragmentSmack was found in the way the Linux kernel handled reassembly of fragmented IPv4 and IPv6 packets. A remote attacker could use this flaw to trigger time and calculation expensive fragment reassembly algorithms by sending specially crafted packets which could lead to a CPU saturation and hence a denial of service on the system.

External References:

https://access.redhat.com/articles/3553061

https://www.kb.cert.org/vuls/id/641765

A fix is a merge commit in the Linux kernel tree:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c30f1fc041b74ecdb072dd44f858750414b8b19f

consisting of the following commits:

7969e5c40dfd04799d4341f1b7cd266b6e47f227 385114dec8a49b5e5945e77ba7de6356106713f4 fa0f527358bd900ef92f925878ed6bfbd51305cc

Other sources

The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size.

— Launchpad

Affected Software

197 affected componentsFixes available
Linux Linux kernel>=3.9<=4.18
redhat Enterprise Linux Desktop=6.0
redhat Enterprise Linux Desktop=7.0
redhat Enterprise Linux Server=6.0
redhat Enterprise Linux Server=7.0
redhat Enterprise Linux Server Aus=6.4
redhat Enterprise Linux Server Aus=6.5
redhat Enterprise Linux Server Aus=6.6
redhat Enterprise Linux Server Aus=7.2
redhat Enterprise Linux Server Aus=7.3
redhat Enterprise Linux Server Aus=7.4
redhat Enterprise Linux Server Eus=6.7
redhat Enterprise Linux Server Eus=7.3
redhat Enterprise Linux Server Eus=7.4
redhat Enterprise Linux Server Eus=7.5
redhat Enterprise Linux Server Tus=6.6
redhat Enterprise Linux Server Tus=7.2
redhat Enterprise Linux Server Tus=7.3
redhat Enterprise Linux Server Tus=7.4
redhat Enterprise Linux Workstation=6.0
redhat Enterprise Linux Workstation=7.0
Debian Debian Linux=8.0
Debian Debian Linux=9.0
Canonical Ubuntu Linux=12.04
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Microsoft Windows 10
Microsoft Windows 10=1607
Microsoft Windows 10=1703
Microsoft Windows 10=1709
Microsoft Windows 10=1803
Microsoft Windows 7=sp1
Microsoft Windows 8.1
Microsoft Windows RT 8.1
Microsoft Windows Server 2008=sp2
Microsoft Windows Server 2008=r2-sp1
Microsoft Windows Server 2008 Itanium=r2-sp1
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016
Microsoft Windows Server 2016=1709
Microsoft Windows Server 2016=1803
F5 BIG-IP Access Policy Manager>=11.5.1<11.6.5.1
F5 BIG-IP Access Policy Manager>=12.1.0<12.1.5
F5 BIG-IP Access Policy Manager>=13.0.0<13.1.3
F5 BIG-IP Access Policy Manager>=14.0.0<14.0.1.1
F5 BIG-IP Access Policy Manager>=14.1.0<14.1.2.4
F5 BIG-IP Advanced Firewall Manager>=11.5.1<11.6.5.1
F5 BIG-IP Advanced Firewall Manager>=12.1.0<12.1.5
F5 BIG-IP Advanced Firewall Manager>=13.0.0<13.1.3
F5 BIG-IP Advanced Firewall Manager>=14.0.0<14.0.1.1
F5 BIG-IP Advanced Firewall Manager>=14.1.0<14.1.2.4
F5 BIG-IP Analytics>=11.5.1<11.6.5.1
F5 BIG-IP Analytics>=12.1.0<12.1.5
F5 BIG-IP Analytics>=13.0.0<13.1.3
F5 BIG-IP Analytics>=14.0.0<14.0.1.1
F5 BIG-IP Analytics>=14.1.0<14.1.2.4
F5 Big-ip Application Acceleration Manager>=11.5.1<11.6.5.1
F5 Big-ip Application Acceleration Manager>=12.1.0<12.1.5
F5 Big-ip Application Acceleration Manager>=13.0.0<13.1.3
F5 Big-ip Application Acceleration Manager>=14.0.0<14.0.1.1
F5 Big-ip Application Acceleration Manager>=14.1.0<14.1.2.4
F5 BIG-IP Application Security Manager>=11.5.1<11.6.5.1
F5 BIG-IP Application Security Manager>=12.1.0<12.1.5
F5 BIG-IP Application Security Manager>=13.0.0<13.1.3
F5 BIG-IP Application Security Manager>=14.0.0<14.0.1.1
F5 BIG-IP Application Security Manager>=14.1.0<14.1.2.4
F5 Big-ip Domain Name System>=11.5.1<11.6.5.1
F5 Big-ip Domain Name System>=12.1.0<12.1.5
F5 Big-ip Domain Name System>=13.0.0<13.1.3
F5 Big-ip Domain Name System>=14.0.0<14.0.1.1
F5 Big-ip Domain Name System>=14.1.0<14.1.2.4
F5 BIG-IP Edge Gateway>=11.5.1<11.6.5.1
F5 BIG-IP Edge Gateway>=12.1.0<12.1.5
F5 BIG-IP Edge Gateway>=13.0.0<13.1.3
F5 BIG-IP Edge Gateway>=14.0.0<14.0.1.1
F5 BIG-IP Edge Gateway>=14.1.0<14.1.2.4
F5 Big-ip Fraud Protection Service>=11.5.1<11.6.5.1
F5 Big-ip Fraud Protection Service>=12.1.0<12.1.5
F5 Big-ip Fraud Protection Service>=13.0.0<13.1.3
F5 Big-ip Fraud Protection Service>=14.0.0<14.0.1.1
F5 Big-ip Fraud Protection Service>=14.1.0<14.1.2.4
F5 Big-ip Global Traffic Manager>=11.5.1<11.6.5.1
F5 Big-ip Global Traffic Manager>=12.1.0<12.1.5
F5 Big-ip Global Traffic Manager>=13.0.0<13.1.3
F5 Big-ip Global Traffic Manager>=14.0.0<14.0.1.1
F5 Big-ip Global Traffic Manager>=14.1.0<14.1.2.4
F5 Big-ip Link Controller>=11.5.1<11.6.5.1
F5 Big-ip Link Controller>=12.1.0<12.1.5
F5 Big-ip Link Controller>=13.0.0<13.1.3
F5 Big-ip Link Controller>=14.0.0<14.0.1.1
F5 Big-ip Link Controller>=14.1.0<14.1.2.4
F5 Big-ip Local Traffic Manager>=11.5.1<11.6.5.1
F5 Big-ip Local Traffic Manager>=12.1.0<12.1.5
F5 Big-ip Local Traffic Manager>=13.0.0<13.1.3
F5 Big-ip Local Traffic Manager>=14.0.0<14.0.1.1
F5 Big-ip Local Traffic Manager>=14.1.0<14.1.2.4
F5 Big-ip Policy Enforcement Manager>=11.5.1<11.6.5.1
F5 Big-ip Policy Enforcement Manager>=12.1.0<12.1.5
F5 Big-ip Policy Enforcement Manager>=13.0.0<13.1.3
F5 Big-ip Policy Enforcement Manager>=14.0.0<14.0.1.1
F5 Big-ip Policy Enforcement Manager>=14.1.0<14.1.2.4
F5 Big-ip Webaccelerator>=11.5.1<11.6.5.1
F5 Big-ip Webaccelerator>=12.1.0<12.1.5
F5 Big-ip Webaccelerator>=13.0.0<13.1.3
F5 Big-ip Webaccelerator>=14.0.0<14.0.1.1
F5 Big-ip Webaccelerator>=14.1.0<14.1.2.4
Siemens Ruggedcom Rm1224 Firmware<6.1
Siemens RUGGEDCOM RM1224
Siemens Ruggedcom Rox Ii Firmware<2.13.3
Siemens Ruggedcom Rox Ii
Siemens Scalance M-800 Firmware<6.1
Siemens SCALANCE M-800
Siemens Scalance S615 Firmware<6.1
Siemens SCALANCE S615
Siemens Scalance Sc-600 Firmware<2.0
Siemens SCALANCE SC-600
Siemens Scalance W1700 Ieee 802.11ac Firmware<2.0
Siemens Scalance W1700 Ieee 802.11ac
Siemens Scalance W700 Ieee 802.11a\/b\/g\/n Firmware<6.4
Siemens Scalance W700 Ieee 802.11a\/b\/g\/n
Siemens Simatic Net Cp 1242-7 Firmware<3.2
Siemens Simatic Net Cp 1242-7
Siemens Simatic Net Cp 1243-1 Firmware<3.2
Siemens Simatic Net Cp 1243-1
Siemens Simatic Net Cp 1243-7 Lte Eu Firmware<3.2
Siemens Simatic Net Cp 1243-7 Lte Eu
Siemens Simatic Net Cp 1243-7 Lte Us Firmware<3.2
Siemens Simatic Net Cp 1243-7 Lte Us
Siemens Simatic Net Cp 1243-8 Irc Firmware<3.2
Siemens Simatic Net Cp 1243-8 Irc
Siemens Simatic Net Cp 1542sp-1 Firmware<2.1
Siemens Simatic Net Cp 1542sp-1
Siemens Simatic Net Cp 1542sp-1 Irc Firmware<2.1
Siemens Simatic Net Cp 1542sp-1 Irc
Siemens Simatic Net Cp 1543-1 Firmware<2.2
Siemens Simatic Net Cp 1543-1
Siemens Simatic Net Cp 1543sp-1 Firmware<2.1
Siemens Simatic Net Cp 1543sp-1
Siemens Simatic Rf185c Firmware<1.3
Siemens Simatic Rf185c
Siemens Simatic Rf186c Firmware<1.3
Siemens Simatic Rf186c
Siemens Simatic Rf186ci Firmware<1.3
Siemens Simatic Rf186ci
Siemens Simatic Rf188 Firmware<1.3
Siemens Simatic Rf188
Siemens Simatic Rf188ci Firmware<1.3
Siemens Simatic Rf188ci
Siemens Sinema Remote Connect Server Firmware>=1.1<2.0.1
Siemens SINEMA Remote Connect Server
All of the following
Siemens Ruggedcom Rm1224 Firmware<6.1
Siemens RUGGEDCOM RM1224
All of the following
Siemens Ruggedcom Rox Ii Firmware<2.13.3
Siemens Ruggedcom Rox Ii
All of the following
Siemens Scalance M-800 Firmware<6.1
Siemens SCALANCE M-800
All of the following
Siemens Scalance S615 Firmware<6.1
Siemens SCALANCE S615
All of the following
Siemens Scalance Sc-600 Firmware<2.0
Siemens SCALANCE SC-600
All of the following
Siemens Scalance W1700 Ieee 802.11ac Firmware<2.0
Siemens Scalance W1700 Ieee 802.11ac
All of the following
Siemens Scalance W700 Ieee 802.11a\/b\/g\/n Firmware<6.4
Siemens Scalance W700 Ieee 802.11a\/b\/g\/n
All of the following
Siemens Simatic Net Cp 1242-7 Firmware<3.2
Siemens Simatic Net Cp 1242-7
All of the following
Siemens Simatic Net Cp 1243-1 Firmware<3.2
Siemens Simatic Net Cp 1243-1
All of the following
Siemens Simatic Net Cp 1243-7 Lte Eu Firmware<3.2
Siemens Simatic Net Cp 1243-7 Lte Eu
All of the following
Siemens Simatic Net Cp 1243-7 Lte Us Firmware<3.2
Siemens Simatic Net Cp 1243-7 Lte Us
All of the following
Siemens Simatic Net Cp 1243-8 Irc Firmware<3.2
Siemens Simatic Net Cp 1243-8 Irc
All of the following
Siemens Simatic Net Cp 1542sp-1 Firmware<2.1
Siemens Simatic Net Cp 1542sp-1
All of the following
Siemens Simatic Net Cp 1542sp-1 Irc Firmware<2.1
Siemens Simatic Net Cp 1542sp-1 Irc
All of the following
Siemens Simatic Net Cp 1543-1 Firmware<2.2
Siemens Simatic Net Cp 1543-1
All of the following
Siemens Simatic Net Cp 1543sp-1 Firmware<2.1
Siemens Simatic Net Cp 1543sp-1
All of the following
Siemens Simatic Rf185c Firmware<1.3
Siemens Simatic Rf185c
All of the following
Siemens Simatic Rf186c Firmware<1.3
Siemens Simatic Rf186c
All of the following
Siemens Simatic Rf186ci Firmware<1.3
Siemens Simatic Rf186ci
All of the following
Siemens Simatic Rf188 Firmware<1.3
Siemens Simatic Rf188
All of the following
Siemens Simatic Rf188ci Firmware<1.3
Siemens Simatic Rf188ci
All of the following
Siemens Sinema Remote Connect Server Firmware>=1.1<2.0.1
Siemens SINEMA Remote Connect Server
debian/linux
5.10.223-15.10.262-16.1.176-16.1.180-16.12.94-16.12.101-17.1.7-17.1.8-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 5.10.223-1Fixed in 5.10.262-1Fixed in 6.1.176-1Fixed in 6.1.180-1Fixed in 6.12.94-1Fixed in 6.12.101-1Fixed in 7.1.7-1Fixed in 7.1.8-1
  2. Upgrade

    Upgrade linux kernel (IP fragmentation reassembly) to a version that resolves this vulnerability.

    Fixed in 3.9+Patch CVE-2018-5391
  3. Upgrade

    Upgrade linux kernel to a version that resolves this vulnerability.

    Fixed in 3.9+Patch fa0f527358bd900ef92f925878ed6bfbd51305cc
  4. Compensating control

    Mitigate CVE-2018-5391 by preventing access to systems from sending specially crafted IPv4/IPv6 fragments (e.g., use network filtering/ACLs or other network-level controls to block or limit fragmented packet traffic to affected hosts).

Event History

Jul 30, 2018
Data Sourced
via Red Hat·07:11 AM
DescriptionSeverityAffected Software
Sep 6, 2018
CVE Published
via MITRE·09:00 PM
Data Sourced
via MITRE·09:00 PM
DescriptionWeakness
Data Sourced
via NVD·09:29 PM
RemedyDescriptionSeverityWeaknessAffected Software
Aug 26, 2025
Data Sourced
via Ubuntu·04:29 AM
RemedyDescriptionSeverityAffected Software
Sep 11, 2025
Data Sourced
via Launchpad·04:32 AM
Description
Aug 12, 2026
Data Sourced
via Debian·11:52 AM
DescriptionAffected Software
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Frequently Asked Questions

1

What is the vulnerability ID of this Linux kernel vulnerability?

The vulnerability ID of this Linux kernel vulnerability is CVE-2018-5391.

2

What is the severity level of CVE-2018-5391?

CVE-2018-5391 has a severity level of high.

3

What is the affected software for CVE-2018-5391?

The affected software for CVE-2018-5391 includes various versions of the Linux kernel, such as linux-aws, linux-azure, linux-euclid, linux-oem, linux, and more.

4

How can I fix CVE-2018-5391?

To fix CVE-2018-5391, update to the recommended versions of the affected software provided by the respective vendors.

5

Where can I find more information about CVE-2018-5391?

You can find more information about CVE-2018-5391 on the Red Hat and CERT websites, as well as the official Linux kernel git repository.

Company

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