# CVE-2013-4563: Denial of service in n/a

> Remote attackers can cause a kernel panic and denial of service via large IPv6 UDP packets when UDP Fragmentation Offload is enabled.

- **Severity:** High 7.1 (`AV:N/AC:M/Au:N/C:N/I:N/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Nov 2013
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2013-4563, GHSA-8qgm-44j9-8vrh

## What is CVE-2013-4563?

CVE-2013-4563 is a high-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 19 Nov 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The udp6_ufo_fragment function in net/ipv6/udp_offload.c in the Linux kernel through 3.12, when UDP Fragmentation Offload (UFO) is enabled, does not properly perform a certain size comparison before inserting a fragment header, which allows remote attackers to cause a denial of service (panic) via a large IPv6 UDP packet, as demonstrated by use of the Token Bucket Filter (TBF) queueing discipline.

Weakness: CWE-189

## Which versions are affected by CVE-2013-4563?

It affects 2 products.


Products: Canonical Ubuntu Linux, Linux kernel.

## How do I fix CVE-2013-4563?

Apply the vendor's patch.

## Is CVE-2013-4563 being exploited?

There is no known exploitation of CVE-2013-4563 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-4563 and fix it if it is affected.

What it is: CVE-2013-4563 is a high-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 19 Nov 2013. 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-2013-4563 in the wild and no public exploit code.

Affected product: Canonical Ubuntu 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-2013-4563/ (Markdown: https://insights.sbomify.com/CVE-2013-4563/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-4563
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-4563
- OSV: https://osv.dev/vulnerability/CVE-2013-4563

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From sbomify Insights: https://insights.sbomify.com/CVE-2013-4563/
Summaries are generated and may contain mistakes; the official description above is the record.