# CVE-2019-16921: Information disclosure in n/a

> Attackers can read sensitive kernel stack memory due to uninitialized data structures in the HNS RoCE driver.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Sep 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-4f4g-m6h2-8q23, UBUNTU-CVE-2019-16921

## What is CVE-2019-16921?

CVE-2019-16921 is a high-severity vulnerability in Linux kernel, published on 27 Sep 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel before 4.17, hns_roce_alloc_ucontext in drivers/infiniband/hw/hns/hns_roce_main.c does not initialize the resp data structure, which might allow attackers to obtain sensitive information from kernel stack memory, aka CID-df7e40425813.

Weakness: CWE-665 (Improper Initialization)

## Which versions are affected by CVE-2019-16921?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2019-16921?

No fix has been published for CVE-2019-16921 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-16921 being exploited?

There is no known exploitation of CVE-2019-16921 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-16921 and fix it if it is affected.

What it is: CVE-2019-16921 is a high-severity vulnerability in Linux kernel, published on 27 Sep 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-2019-16921 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2019-16921/ (Markdown: https://insights.sbomify.com/CVE-2019-16921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-16921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-16921
- OSV: https://osv.dev/vulnerability/CVE-2019-16921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-16921/
Summaries are generated and may contain mistakes; the official description above is the record.