# CVE-2018-19591: Denial of service in n/a

> Attackers can cause resource exhaustion and denial of service by triggering a socket descriptor leak in glibc's hostname resolution logic.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Dec 2018
- **Updated:** 14 Oct 2026
- **Also known as:** DEBIAN-CVE-2018-19591, GHSA-x2fw-rj3g-6m95, UBUNTU-CVE-2018-19591

## What is CVE-2018-19591?

CVE-2018-19591 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 4 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the GNU C Library (aka glibc or libc6) through 2.28, attempting to resolve a crafted hostname via getaddrinfo() leads to the allocation of a socket descriptor that is not closed. This is related to the if_nametoindex() function.

Weakness: CWE-20 (Improper Input Validation), CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2018-19591?

It affects 2 products.


Products: Fedoraproject Fedora, Gnu Glibc.

## How do I fix CVE-2018-19591?

Apply the vendor's patch.

## Is CVE-2018-19591 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-19591 exists.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-19591 and fix it if it is affected.

What it is: CVE-2018-19591 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 4 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-19591 exists.

Affected product: Fedoraproject Fedora. 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-2018-19591/ (Markdown: https://insights.sbomify.com/CVE-2018-19591/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-19591
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-19591
- OSV: https://osv.dev/vulnerability/CVE-2018-19591

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-19591/
Summaries are generated and may contain mistakes; the official description above is the record.