# CVE-2016-1981: Denial of service in n/a

> A privileged guest user can crash the QEMU instance via an infinite loop in e1000 NIC emulation, causing denial of service.

- **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:** Yes
- **Published:** 29 Dec 2016
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-1981, GHSA-ch9p-9c28-4r3p, UBUNTU-CVE-2016-1981

## What is CVE-2016-1981?

CVE-2016-1981 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 29 Dec 2016. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

QEMU (aka Quick Emulator) built with the e1000 NIC emulation support is vulnerable to an infinite loop issue. It could occur while processing data via transmit or receive descriptors, provided the initial receive/transmit descriptor head (TDH/RDH) is set outside the allocated descriptor buffer. A privileged user inside guest could use this flaw to crash the QEMU instance resulting in DoS.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2016-1981?

It affects 2 products.


Products: Debian Debian Linux, Qemu Qemu.

## How do I fix CVE-2016-1981?

Apply the vendor's patch.

## Is CVE-2016-1981 being exploited?

There is no known exploitation of CVE-2016-1981 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-1981 and fix it if it is affected.

What it is: CVE-2016-1981 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 29 Dec 2016. 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-2016-1981 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2016-1981/ (Markdown: https://insights.sbomify.com/CVE-2016-1981/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-1981
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-1981
- OSV: https://osv.dev/vulnerability/CVE-2016-1981

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-1981/
Summaries are generated and may contain mistakes; the official description above is the record.