# CVE-2019-17420: Security feature bypass in n/a

> Attackers can bypass HTTP header signature alerts in Suricata by sending responses with single CRLF endings, evading detection.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Oct 2019
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-17420, GHSA-9gx8-hhv8-hw56, UBUNTU-CVE-2019-17420

## What is CVE-2019-17420?

CVE-2019-17420 is a medium-severity vulnerability in n/a, published on 9 Oct 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In OISF LibHTP before 0.5.31, as used in Suricata 4.1.4 and other products, an HTTP protocol parsing error causes the http_header signature to not alert on a response with a single \r\n ending.

Weakness: CWE-459 (Incomplete Cleanup)

## Which versions are affected by CVE-2019-17420?

It affects 2 products.


Products: Oisf Libhtp, Suricata-Ids Suricata.

## How do I fix CVE-2019-17420?

Upgrade to a fixed version.

## Is CVE-2019-17420 being exploited?

There is no known exploitation of CVE-2019-17420 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-10243](https://insights.sbomify.com/CVE-2018-10243/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-53537](https://insights.sbomify.com/CVE-2025-53537/): LibHTP's memory leak with lzma can lead to resource starvation (high 7.5)
- [CVE-2024-45797](https://insights.sbomify.com/CVE-2024-45797/): LibHTP's unbounded header handling leads to denial service (high 7.5)
- [CVE-2024-28871](https://insights.sbomify.com/CVE-2024-28871/): Excessive CPU used on malformed traffic (high 7.5)
- [CVE-2015-0928](https://insights.sbomify.com/CVE-2015-0928/): Null dereference in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-17420 and fix it if it is affected.

What it is: CVE-2019-17420 is a medium-severity vulnerability in n/a, published on 9 Oct 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-2019-17420 in the wild and no public exploit code.

Affected product: n/a. 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-2019-17420/ (Markdown: https://insights.sbomify.com/CVE-2019-17420/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-17420
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-17420
- OSV: https://osv.dev/vulnerability/CVE-2019-17420

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-17420/
Summaries are generated and may contain mistakes; the official description above is the record.