# CVE-2023-34319: Linux: buffer overrun in netback due to unusual packet

> A buffer overrun in the Linux netback driver allows attackers to cause denial of service or execute code via specially crafted network packets.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 22 Sep 2023
- **Updated:** 14 Oct 2026
- **Also known as:** DEBIAN-CVE-2023-34319, UBUNTU-CVE-2023-34319

## What is CVE-2023-34319?

CVE-2023-34319 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 22 Sep 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The fix for XSA-423 added logic to Linux'es netback driver to deal with
a frontend splitting a packet in a way such that not all of the headers
would come in one piece.  Unfortunately the logic introduced there
didn't account for the extreme case of the entire packet being split
into as many pieces as permitted by the protocol, yet still being
smaller than the area that's specially dealt with to keep all (possible)
headers together.  Such an unusual packet would therefore trigger a
buffer overrun in the driver.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2023-34319?

It affects 3 products.


Products: Debian Debian Linux, Linux kernel, Xen Xen.

## How do I fix CVE-2023-34319?

Apply the vendor's patch.

## Is CVE-2023-34319 being exploited?

There is no known exploitation of CVE-2023-34319 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-2023-34319 and fix it if it is affected.

What it is: CVE-2023-34319 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 22 Sep 2023. 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-2023-34319 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-2023-34319/ (Markdown: https://insights.sbomify.com/CVE-2023-34319/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-34319
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-34319
- OSV: https://osv.dev/vulnerability/CVE-2023-34319

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-34319/
Summaries are generated and may contain mistakes; the official description above is the record.