# CVE-2018-17189: Denial of service in Apache HTTP Server

> Attackers can cause denial of service by sending slow request bodies to HTTP/2 resources, exhausting server threads.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jan 2019
- **Updated:** 17 Sep 2024
- **Also known as:** ALPINE-CVE-2018-17189, CLEANSTART-2026-XI76483, DEBIAN-CVE-2018-17189, GHSA-xcwr-pcwv-7gm8, UBUNTU-CVE-2018-17189

## What is CVE-2018-17189?

CVE-2018-17189 is a medium-severity denial of service vulnerability in Apache Http Server, published on 30 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Apache HTTP server versions 2.4.37 and prior, by sending request bodies in a slow loris way to plain resources, the h2 stream for that request unnecessarily occupied a server thread cleaning up that incoming data. This affects only HTTP/2 (mod_http2) connections.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2018-17189?

It affects 12 products.


Products: Apache Http Server, Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Netapp Santricity Cloud Connector, Netapp Storage Automation Store, Oracle Enterprise Manager Ops Center, Oracle Hospitality Guest Access, Oracle Instantis Enterprisetrack, Oracle Retail Xstore Point of Service, Oracle Sun Zfs Storage Appliance Kit, Redhat Jboss Core Services.

## How do I fix CVE-2018-17189?

Upgrade to a fixed version.

## Is CVE-2018-17189 being exploited?

There is no known exploitation of CVE-2018-17189 in the wild and no public exploit code.

## Other vulnerabilities in Apache Http Server

- [CVE-2021-42013](https://insights.sbomify.com/CVE-2021-42013/): Apache HTTP Server Path Traversal (critical 9.8, exploited in the wild)
- [CVE-2024-38475](https://insights.sbomify.com/CVE-2024-38475/): Apache HTTP Server Improper Escaping of Output (critical 9.1, exploited in the wild)
- [CVE-2021-40438](https://insights.sbomify.com/CVE-2021-40438/): Apache HTTP Server-Side Request Forgery (SSRF) (critical 9.0, exploited in the wild)
- [CVE-2019-0211](https://insights.sbomify.com/CVE-2019-0211/): Apache HTTP Server Privilege Escalation (high 7.8, exploited in the wild)
- [CVE-2021-41773](https://insights.sbomify.com/CVE-2021-41773/): Apache HTTP Server Path Traversal (high 7.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-17189 and fix it if it is affected.

What it is: CVE-2018-17189 is a medium-severity denial of service vulnerability in Apache Http Server, published on 30 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-17189 in the wild and no public exploit code.

Affected product: Apache Http Server. 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-2018-17189/ (Markdown: https://insights.sbomify.com/CVE-2018-17189/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-17189
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-17189
- OSV: https://osv.dev/vulnerability/CVE-2018-17189

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-17189/
Summaries are generated and may contain mistakes; the official description above is the record.