# CVE-2011-1927: Null dereference in n/a

> Remote attackers can cause a denial of service via crafted fragmented packets due to an invalid pointer dereference in the Linux kernel IP fragment handling.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Jun 2012
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-qmg2-c98g-p46x

## What is CVE-2011-1927?

CVE-2011-1927 is a medium-severity vulnerability in Linux kernel, published on 13 Jun 2012. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The ip_expire function in net/ipv4/ip_fragment.c in the Linux kernel before 2.6.39 does not properly construct ICMP_TIME_EXCEEDED packets after a timeout, which allows remote attackers to cause a denial of service (invalid pointer dereference) via crafted fragmented packets.

## Which versions are affected by CVE-2011-1927?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2011-1927?

No fix has been published for CVE-2011-1927 yet. Limit exposure of the affected software until one is available.

## Is CVE-2011-1927 being exploited?

There is no known exploitation of CVE-2011-1927 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-2011-1927 and fix it if it is affected.

What it is: CVE-2011-1927 is a medium-severity vulnerability in Linux kernel, published on 13 Jun 2012. 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-2011-1927 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-2011-1927/ (Markdown: https://insights.sbomify.com/CVE-2011-1927/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-1927
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-1927
- OSV: https://osv.dev/vulnerability/CVE-2011-1927

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-1927/
Summaries are generated and may contain mistakes; the official description above is the record.