# CVE-2017-2647: Null dereference in n/a

> Local attackers can exploit a NULL pointer dereference in the Linux kernel KEYS subsystem to escalate privileges or crash the system.

- **Severity:** High 7.8 (`CVSS:3.0/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:** 31 Mar 2017
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2017-2647, GHSA-6723-4j9m-72qg, RHSA-2020:3836, UBUNTU-CVE-2017-2647

## What is CVE-2017-2647?

CVE-2017-2647 is a high-severity vulnerability in Linux kernel, published on 31 Mar 2017. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The KEYS subsystem in the Linux kernel before 3.18 allows local users to gain privileges or cause a denial of service (NULL pointer dereference and system crash) via vectors involving a NULL value for a certain match field, related to the keyring_search_iterator function in keyring.c.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2017-2647?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `kernel` | Red Hat:rhel_aus:6.6::server | All versions | 0:2.6.32-504.84.1.el6 |
| `kernel-debug` | Red Hat:rhel_aus:6.6::server | All versions | 0:2.6.32-504.84.1.el6 |
| `kernel-debug-debuginfo` | Red Hat:rhel_aus:6.6::server | All versions | 0:2.6.32-504.84.1.el6 |
| `kernel-debug-devel` | Red Hat:rhel_aus:6.6::server | All versions | 0:2.6.32-504.84.1.el6 |
| `kernel-debuginfo` | Red Hat:rhel_aus:6.6::server | All versions | 0:2.6.32-504.84.1.el6 |
| `kernel-debuginfo-common-x86_64` | Red Hat:rhel_aus:6.6::server | All versions | 0:2.6.32-504.84.1.el6 |
| `kernel-devel` | Red Hat:rhel_aus:6.6::server | All versions | 0:2.6.32-504.84.1.el6 |

Products: Linux kernel.

## How do I fix CVE-2017-2647?

Apply the vendor's patch.

## Is CVE-2017-2647 being exploited?

There is no known exploitation of CVE-2017-2647 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-2017-2647 and fix it if it is affected.

What it is: CVE-2017-2647 is a high-severity vulnerability in Linux kernel, published on 31 Mar 2017. 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-2017-2647 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-2017-2647/ (Markdown: https://insights.sbomify.com/CVE-2017-2647/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-2647
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-2647
- OSV: https://osv.dev/vulnerability/CVE-2017-2647

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-2647/
Summaries are generated and may contain mistakes; the official description above is the record.