# What is CVE-2018-5390?

> CVE-2018-5390 is a high-severity flaw (CVSS 7.5) in Linux kernel, published on 6 August 2018. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 71%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2018-5390

## At a glance

- **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.
- **Precursor Intelligence risk score:** 57 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 7.5 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 71% (latest exploit-likelihood forecast)
- **Published:** 6 August 2018
- **Record last updated:** 7 November 2023
- **Main product:** Linux kernel
- **Affected products:** 40

## What is CVE-2018-5390? In plain terms

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline.

### The official description

Linux kernel versions 4.9+ can be forced to make very expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for every incoming packet which can lead to a denial of service.

### What kind of flaw is it?

- CWE-400: Uncontrolled Resource Consumption

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can take it offline

Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`

## Is CVE-2018-5390 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 71%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 71%, 71%, 71%, 71%, 71%, 71%, 71%.

### Timeline

- 6 August 2018: Published
- 7 November 2023: Record last updated
- 24 September 2025: Exploit likelihood fell
- 19 November 2025: Exploit likelihood jumped

### How Precursor Intelligence ranks it

CVE-2018-5390 scores **57 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2018-5390?

The published record lists 40 products. Versions are as published: "4.9 to before 4.18" means from 4.9 up to, but not including, 4.18.

- [Linux kernel](https://www.precursorintelligence.com/product/linux/linux_kernel) by [Linux](https://www.precursorintelligence.com/vendors/linux) (Operating system): 4.9 to before 4.18
- [Advanced Core Operating System](https://www.precursorintelligence.com/product/a10networks/advanced_core_operating_system) by [A10networks](https://www.precursorintelligence.com/vendors/a10networks) (Operating system): 3.2.2, 3.2.2-p5, 4.1.0, 4.1.0-p11, 4.1.1-p8, 4.1.2, 4.1.2-p4, 4.1.4, 4.1.4-p1
- [Enterprise Linux Server Aus](https://www.precursorintelligence.com/product/redhat/enterprise_linux_server_aus) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Operating system): 6.4, 6.5, 6.6, 7.2, 7.3, 7.4
- [Enterprise Linux Server Eus](https://www.precursorintelligence.com/product/redhat/enterprise_linux_server_eus) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Operating system): 6.4, 6.7, 7.2, 7.3, 7.4, 7.5
- [Expressway](https://www.precursorintelligence.com/product/cisco/expressway) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): x8.10, x8.10.1, x8.10.2, x8.10.3, x8.10.4, x8.11
- [Telepresence Video Communication Server Firmware](https://www.precursorintelligence.com/product/cisco/telepresence_video_communication_server_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): x8.10, x8.10.1, x8.10.2, x8.10.3, x8.10.4, x8.11
- [Telepresence Conductor Firmware](https://www.precursorintelligence.com/product/cisco/telepresence_conductor_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): xc4.3, xc4.3.1, xc4.3.2, xc4.3.3, xc4.3.4
- [Big-IP Access Policy Manager](https://www.precursorintelligence.com/product/f5/big-ip_access_policy_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Advanced Firewall Manager](https://www.precursorintelligence.com/product/f5/big-ip_advanced_firewall_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Analytics](https://www.precursorintelligence.com/product/f5/big-ip_analytics) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Application Acceleration Manager](https://www.precursorintelligence.com/product/f5/big-ip_application_acceleration_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Application Security Manager](https://www.precursorintelligence.com/product/f5/big-ip_application_security_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Domain Name System](https://www.precursorintelligence.com/product/f5/big-ip_domain_name_system) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Edge Gateway](https://www.precursorintelligence.com/product/f5/big-ip_edge_gateway) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1. to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Fraud Protection Service](https://www.precursorintelligence.com/product/f5/big-ip_fraud_protection_service) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Global Traffic Manager](https://www.precursorintelligence.com/product/f5/big-ip_global_traffic_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Link Controller](https://www.precursorintelligence.com/product/f5/big-ip_link_controller) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Local Traffic Manager](https://www.precursorintelligence.com/product/f5/big-ip_local_traffic_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.0.0 to 12.1.3, after 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Policy Enforcement Manager](https://www.precursorintelligence.com/product/f5/big-ip_policy_enforcement_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Big-IP Webaccelerator](https://www.precursorintelligence.com/product/f5/big-ip_webaccelerator) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.1 to 11.6.3, 12.1.0 to 12.1.3, 13.0.0 to 13.1.1, 14.0.0
- [Enterprise Linux Server Tus](https://www.precursorintelligence.com/product/redhat/enterprise_linux_server_tus) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Operating system): 6.6, 7.2, 7.3, 7.4
- [Ubuntu Linux](https://www.precursorintelligence.com/product/canonical/ubuntu_linux) by [Canonical](https://www.precursorintelligence.com/vendors/canonical) (Operating system): 12.04, 14.04, 16.04, 18.04
- [Aruba Clearpass Policy Manager](https://www.precursorintelligence.com/product/hp/aruba_clearpass_policy_manager) by [HP](https://www.precursorintelligence.com/vendors/hp) (Application): 6.6.0 to 6.6.9, 6.7.0 to 6.7.5
- [Debian Linux](https://www.precursorintelligence.com/product/debian/debian_linux) by [Debian](https://www.precursorintelligence.com/vendors/debian) (Operating system): 8.0, 9.0
- [Meeting Management](https://www.precursorintelligence.com/product/cisco/meeting_management) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 1.0, 1.0.1
- [Traffix Systems Signaling Delivery Controller](https://www.precursorintelligence.com/product/f5/traffix_systems_signaling_delivery_controller) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 4.4.0, 5.0.0 to 5.1.0
- [Aruba Airwave Amp](https://www.precursorintelligence.com/product/hp/aruba_airwave_amp) by [HP](https://www.precursorintelligence.com/vendors/hp) (Application): before 8.2.7.1
- [Collaboration Meeting Rooms](https://www.precursorintelligence.com/product/cisco/collaboration_meeting_rooms) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 1.0
- [Digital Network Architecture Center](https://www.precursorintelligence.com/product/cisco/digital_network_architecture_center) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 1.2
- [Enterprise Linux Desktop](https://www.precursorintelligence.com/product/redhat/enterprise_linux_desktop) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Operating system): 7.0
- [Enterprise Linux Server](https://www.precursorintelligence.com/product/redhat/enterprise_linux_server) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Operating system): 7.0
- [Enterprise Linux Workstation](https://www.precursorintelligence.com/product/redhat/enterprise_linux_workstation) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Operating system): 7.0
- [Expressway Series](https://www.precursorintelligence.com/product/cisco/expressway_series) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): version not specified
- [Network Assurance Engine](https://www.precursorintelligence.com/product/cisco/network_assurance_engine) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 2.1(1a)
- [Telepresence Conductor](https://www.precursorintelligence.com/product/cisco/telepresence_conductor) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Telepresence Video Communication Server](https://www.precursorintelligence.com/product/cisco/telepresence_video_communication_server) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Threat Grid-Cloud](https://www.precursorintelligence.com/product/cisco/threat_grid-cloud) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): version not specified
- [Virtualization](https://www.precursorintelligence.com/product/redhat/virtualization) by [Red Hat](https://www.precursorintelligence.com/vendors/redhat) (Application): 4.0
- [Webex Hybrid Data Security](https://www.precursorintelligence.com/product/cisco/webex_hybrid_data_security) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): version not specified
- [Webex Video Mesh](https://www.precursorintelligence.com/product/cisco/webex_video_mesh) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): version not specified

## How do I fix CVE-2018-5390?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [git.kernel.org](https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=1a4f14bab1868b443f0dd3c55b689a478f82e72e) (Patch, Vendor advisory)
- [oracle.com](https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html) (Patch, Third-party advisory)
- [a10networks.com](https://www.a10networks.com/support/security-advisories/tcp-ip-cve-2018-5390-segmentsmack) (Mitigation, Third-party advisory)
- [arubanetworks.com](http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2018-004.txt) (Third-party advisory)
- [huawei.com](http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20181031-02-linux-en) (Third-party advisory)
- [openwall.com](http://www.openwall.com/lists/oss-security/2019/06/28/2) (Mailing list, Third-party advisory)
- [openwall.com](http://www.openwall.com/lists/oss-security/2019/07/06/3) (Mailing list, Third-party advisory)
- [openwall.com](http://www.openwall.com/lists/oss-security/2019/07/06/4) (Mailing list, Third-party advisory)
- [securityfocus.com](http://www.securityfocus.com/bid/104976) (Third-party advisory, Vulnerability database)
- [securitytracker.com](http://www.securitytracker.com/id/1041424) (Third-party advisory, Vulnerability database)
- [securitytracker.com](http://www.securitytracker.com/id/1041434) (Third-party advisory, Vulnerability database)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2384) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2395) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2402) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2403) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2645) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2776) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2785) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2789) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2790) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2791) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2924) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2933) (Third-party advisory)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2018:2948) (Third-party advisory)
- [cert-portal.siemens.com](https://cert-portal.siemens.com/productcert/pdf/ssa-377115.pdf) (Third-party advisory)
- [help.ecostruxureit.com](https://help.ecostruxureit.com/display/public/UADCE725/Security+fixes+in+StruxureWare+Data+Center+Expert+v7.6.0) (Third-party advisory)
- [lists.debian.org](https://lists.debian.org/debian-lts-announce/2018/08/msg00014.html) (Third-party advisory)
- [security.netapp.com](https://security.netapp.com/advisory/ntap-20180815-0003/) (Third-party advisory)
- [support.f5.com](https://support.f5.com/csp/article/K95343321) (Third-party advisory)
- [support.f5.com](https://support.f5.com/csp/article/K95343321?utm_source=f5support&amp%3Butm_medium=RSS)
- [tools.cisco.com](https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180824-linux-tcp) (Third-party advisory)
- [usn.ubuntu.com](https://usn.ubuntu.com/3732-1/) (Third-party advisory)
- [usn.ubuntu.com](https://usn.ubuntu.com/3732-2/) (Third-party advisory)
- [usn.ubuntu.com](https://usn.ubuntu.com/3741-1/) (Third-party advisory)
- [usn.ubuntu.com](https://usn.ubuntu.com/3741-2/) (Third-party advisory)
- [usn.ubuntu.com](https://usn.ubuntu.com/3742-1/) (Third-party advisory)
- [usn.ubuntu.com](https://usn.ubuntu.com/3742-2/) (Third-party advisory)
- [usn.ubuntu.com](https://usn.ubuntu.com/3763-1/) (Third-party advisory)
- [debian.org](https://www.debian.org/security/2018/dsa-4266) (Third-party advisory)
- [kb.cert.org](https://www.kb.cert.org/vuls/id/962459) (Third-party advisory, Government resource)
- [oracle.com](https://www.oracle.com/security-alerts/cpujul2020.html) (Third-party advisory)
- [synology.com](https://www.synology.com/support/security/Synology_SA_18_41) (Third-party advisory)

## Questions

### What is CVE-2018-5390?

CVE-2018-5390 is a high-severity flaw in Linux kernel, published on 6 August 2018. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline.

### How serious is CVE-2018-5390?

It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2018-5390 is 57 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

### Is CVE-2018-5390 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 71%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2018-5390 affect?

For Linux kernel: 4.9 to before 4.18. The record lists 40 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2018-5390?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2018-5390 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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