# CVE-2024-43167: Unbound: null pointer dereference in unbound

> A null pointer dereference in the Unbound library allows attackers to cause a denial of service via specific API call sequences.

- **Severity:** Low 2.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 8 Aug 2024
- **Updated:** 3 Nov 2025
- **Also known as:** AZL-47771, AZL-47779, DEBIAN-CVE-2024-43167, GHSA-f34v-4q4f-pf5q, MGASA-2024-0293, SUSE-SU-2024:3074-1, SUSE-SU-2024:3111-1, UBUNTU-CVE-2024-43167, openSUSE-SU-2024:14270-1

## What is CVE-2024-43167?

CVE-2024-43167 is a low-severity vulnerability in Red Hat Enterprise Linux 6, published on 8 Aug 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

DISPUTE NOTE: this issue does not pose a security risk as it (according to analysis by the original software developer, NLnet Labs) falls within the expected functionality and security controls of the application. Red Hat has made a claim that there is a security risk within Red Hat products. NLnet Labs has no further information about the claim, and suggests that affected Red Hat customers refer to available Red Hat documentation or support channels. ORIGINAL DESCRIPTION: A NULL pointer dereference flaw was found in the ub_ctx_set_fwd function in Unbound. This issue could allow an attacker who can invoke specific sequences of API calls to cause a segmentation fault. When certain API functions such as ub_ctx_set_fwd and ub_ctx_resolvconf are called in a particular order, the program attempts to read from a NULL pointer, leading to a crash. This issue can result in a denial of service by causing the application to terminate unexpectedly.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-43167?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `unbound` | SUSE:Linux Enterprise Micro 5.5 | All versions | 1.20.0-150100.10.16.1 |
| `unbound` | SUSE:Linux Enterprise Module for Basesystem 15 SP5 | All versions | 1.20.0-150100.10.16.1 |
| `unbound` | SUSE:Linux Enterprise Module for Basesystem 15 SP6 | All versions | 1.20.0-150600.23.6.1 |
| `unbound` | SUSE:Linux Enterprise Module for Package Hub 15 SP5 | All versions | 1.20.0-150100.10.16.1 |
| `unbound` | SUSE:Linux Enterprise Module for Package Hub 15 SP6 | All versions | 1.20.0-150600.23.6.1 |
| `unbound` | openSUSE:Leap 15.5 | All versions | 1.20.0-150100.10.16.1 |
| `unbound` | openSUSE:Leap 15.6 | All versions | 1.20.0-150600.23.6.1 |
| `unbound` | openSUSE:Tumbleweed | All versions | 1.21.0-1.1 |

## How do I fix CVE-2024-43167?

Apply the vendor's patch.

## Is CVE-2024-43167 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-43167 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-43167 and fix it if it is affected.

What it is: CVE-2024-43167 is a low-severity vulnerability in Red Hat Enterprise Linux 6, published on 8 Aug 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-43167 exists.

Affected product: Red Hat Enterprise Linux 6. 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-2024-43167/ (Markdown: https://insights.sbomify.com/CVE-2024-43167/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-43167
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-43167
- OSV: https://osv.dev/vulnerability/CVE-2024-43167

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-43167/
Summaries are generated and may contain mistakes; the official description above is the record.