# CVE-2018-17204: 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.


- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 19 Sep 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-17204, GHSA-4wv2-475w-c2fw, RHBA-2018:3683, UBUNTU-CVE-2018-17204

## What is CVE-2018-17204?

CVE-2018-17204 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 19 Sep 2018. 

### Official 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.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2018-17204?

It affects 4 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `redhat-release-virtualization-host` | Red Hat:enterprise_linux:7::hypervisor | All versions | 0:4.2-7.5.el7 |
| `redhat-virtualization-host` | Red Hat:enterprise_linux:7::hypervisor | All versions | 0:4.2-20181121.0.el7_6 |
| `redhat-virtualization-host-image-update` | Red Hat:enterprise_linux:7::hypervisor | All versions | 0:4.2-20181121.0.el7_6 |
| `redhat-virtualization-host-image-update-placeholder` | Red Hat:enterprise_linux:7::hypervisor | All versions | 0:4.2-7.5.el7 |

Products: Canonical Ubuntu Linux, Debian Debian Linux, Openvswitch Openvswitch, Redhat Openstack.

## How do I fix CVE-2018-17204?

Upgrade to a fixed version.

## Is CVE-2018-17204 being exploited?

There is no known exploitation of CVE-2018-17204 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-17204 and fix it if it is affected.

What it is: CVE-2018-17204 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 19 Sep 2018. 
Exploitation: There is no known exploitation of CVE-2018-17204 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-17204/ (Markdown: https://insights.sbomify.com/CVE-2018-17204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-17204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-17204
- OSV: https://osv.dev/vulnerability/CVE-2018-17204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-17204/
Summaries are generated and may contain mistakes; the official description above is the record.