CVE-2018-17204

Name: CVE-2018-17204
Creator: NVD / NIST
Published: 2018-09-19T16:29:00.897+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 1.91%

Last modified Jun 17, 2026

CVE-2018-17204 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting parse_group_prop_ntr_selection_method in lib/ofp-util.c. When decoding a group mod, it validates the group type and command after the whole group mod has been decoded. EPSS estimates a 1.91% chance of exploitation in the next 30 days.

Description

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting parse_group_prop_ntr_selection_method in lib/ofp-util.c. When decoding a group mod, it validates the group type and command after the whole group mod has been decoded. The OF1.5 decoder, however, tries to use the type and command earlier, when it might still be invalid. This causes an assertion failure (via OVS_NOT_REACHED). ovs-vswitchd does not enable support for OpenFlow 1.5 by default.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

1.91%

77.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-617

Affected Software

Vendor	Product	Versions
Openvswitch	Openvswitch	>= 2.7.0, <= 2.7.6
Redhat	Openstack	10
Redhat	Openstack	13
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	18.04
Debian	Debian Linux	9.0

References

https://access.redhat.com/errata/RHSA-2018:3500Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0053Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0081Third Party Advisory
https://github.com/openvswitch/ovs/commit/4af6da3b275b764b1afe194df6499b33d2bf4cdePatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/02/msg00032.htmlMailing List, Third Party Advisory
https://usn.ubuntu.com/3873-1/Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3500Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0053Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0081Third Party Advisory
https://github.com/openvswitch/ovs/commit/4af6da3b275b764b1afe194df6499b33d2bf4cdePatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/02/msg00032.htmlMailing List, Third Party Advisory
https://usn.ubuntu.com/3873-1/Third Party Advisory

Timeline

Published: Sep 19, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-17204?

How severe is CVE-2018-17204?

CVE-2018-17204 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 1.91% probability of exploitation in the next 30 days.

How do I fix CVE-2018-17204?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-17204?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST