# CVE-2019-11867: Null dereference in n/a

> A local attacker can cause a denial of service by sending a zero-sized buffer to the Realtek NDIS driver, triggering a null dereference.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Feb 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-5fj4-62hp-5pfc

## What is CVE-2019-11867?

CVE-2019-11867 is a medium-severity vulnerability in n/a, published on 12 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Realtek NDIS driver rt640x64.sys, file version 10.1.505.2015, fails to do any size checking on an input buffer from user space, which the driver assumes has a size greater than zero bytes. To exploit this vulnerability, an attacker must send an IRP with a system buffer size of 0.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2019-11867?

It affects 1 product.


Products: Realtek Ndis.

## How do I fix CVE-2019-11867?

No fix has been published for CVE-2019-11867 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-11867 being exploited?

There is no known exploitation of CVE-2019-11867 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-11867 and fix it if it is affected.

What it is: CVE-2019-11867 is a medium-severity vulnerability in n/a, published on 12 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-11867 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-2019-11867/ (Markdown: https://insights.sbomify.com/CVE-2019-11867/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-11867
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-11867
- OSV: https://osv.dev/vulnerability/CVE-2019-11867

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-11867/
Summaries are generated and may contain mistakes; the official description above is the record.