# CVE-2019-0197: Denial of service in Apache HTTP Server

> Attackers can crash Apache HTTP Server by sending specific HTTP/2 upgrade requests when HTTP/2 is enabled on HTTP or with H2Upgrade on HTTPS.

- **Severity:** Medium 4.2 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Jun 2019
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2019-0197, CLEANSTART-2026-ZL75334, DEBIAN-CVE-2019-0197, GHSA-g33m-gfwr-29g4, UBUNTU-CVE-2019-0197

## What is CVE-2019-0197?

CVE-2019-0197 is a medium-severity denial of service vulnerability in Apache Http Server, published on 11 Jun 2019. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was found in Apache HTTP Server 2.4.34 to 2.4.38. When HTTP/2 was enabled for a http: host or H2Upgrade was enabled for h2 on a https: host, an Upgrade request from http/1.1 to http/2 that was not the first request on a connection could lead to a misconfiguration and crash. Server that never enabled the h2 protocol or that only enabled it for https: and did not set "H2Upgrade on" are unaffected by this issue.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2019-0197?

It affects 11 products.


Products: Apache Http Server, Canonical Ubuntu Linux, Fedoraproject Fedora, Opensuse Leap, Oracle Communications Session Report Manager, Oracle Communications Session Route Manager, Oracle Enterprise Manager Ops Center, Oracle Http Server, Oracle Instantis Enterprisetrack, Oracle Retail Xstore Point of Service, Redhat Jboss Core Services.

## How do I fix CVE-2019-0197?

Upgrade to a fixed version.

## Is CVE-2019-0197 being exploited?

There is no known exploitation of CVE-2019-0197 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-2019-0197 and fix it if it is affected.

What it is: CVE-2019-0197 is a medium-severity denial of service vulnerability in Apache Http Server, published on 11 Jun 2019. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-0197 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-2019-0197/ (Markdown: https://insights.sbomify.com/CVE-2019-0197/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-0197
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-0197
- OSV: https://osv.dev/vulnerability/CVE-2019-0197

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-0197/
Summaries are generated and may contain mistakes; the official description above is the record.