# CVE-2011-1021: Privilege escalation in n/a

> Local root users can modify arbitrary kernel memory via debugfs, enabling privilege escalation or code execution.

- **Severity:** Low 3.6 (`AV:L/AC:L/Au:N/C:N/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Jun 2012
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-42f2-xvqw-p5x2

## What is CVE-2011-1021?

CVE-2011-1021 is a low-severity vulnerability in Linux kernel, published on 21 Jun 2012. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

drivers/acpi/debugfs.c in the Linux kernel before 3.0 allows local users to modify arbitrary kernel memory locations by leveraging root privileges to write to the /sys/kernel/debug/acpi/custom_method file. NOTE: this vulnerability exists because of an incomplete fix for CVE-2010-4347.

Weakness: CWE-264

## Which versions are affected by CVE-2011-1021?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2011-1021?

Apply the vendor's patch.

## Is CVE-2011-1021 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2011-1021 exists.

Public exploit code:

- Linux Kernel < 2.6.37-rc2 - 'ACPI custom_method' Local Privilege Escalation (exploitdb)

## 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-2011-1021 and fix it if it is affected.

What it is: CVE-2011-1021 is a low-severity vulnerability in Linux kernel, published on 21 Jun 2012. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2011-1021 exists.

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-2011-1021/ (Markdown: https://insights.sbomify.com/CVE-2011-1021/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-1021
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-1021
- OSV: https://osv.dev/vulnerability/CVE-2011-1021

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From sbomify Insights: https://insights.sbomify.com/CVE-2011-1021/
Summaries are generated and may contain mistakes; the official description above is the record.