# CVE-2001-1559: Null dereference in n/a

> Local users can cause a denial of service in OpenBSD via a null dereference in the uipc system calls due to incorrect return value handling.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** No
- **Published:** 14 Jul 2005
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-c4g9-53v4-f2qg

## What is CVE-2001-1559?

CVE-2001-1559 is a medium-severity vulnerability in Openbsd Openbsd, published on 14 Jul 2005. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The uipc system calls (uipc_syscalls.c) in OpenBSD 2.9 and 3.0 provide user mode return instead of versus rval kernel mode values to the fdrelease function, which allows local users to cause a denial of service and trigger a null dereference.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2001-1559?

It affects 1 product.


Products: Openbsd Openbsd.

## How do I fix CVE-2001-1559?

No fix has been published for CVE-2001-1559 yet. Limit exposure of the affected software until one is available.

## Is CVE-2001-1559 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2001-1559 exists.

Public exploit code:

- OpenBSD 2.x/3.0 - User Mode Return Value Denial of Service (exploitdb)

## Other vulnerabilities in Openbsd Openbsd

- [CVE-2007-1365](https://insights.sbomify.com/CVE-2007-1365/): Memory corruption in n/a (critical 10.0)
- [CVE-2004-0220](https://insights.sbomify.com/CVE-2004-0220/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0083](https://insights.sbomify.com/CVE-2004-0083/): Memory corruption in n/a (critical 10.0)
- [CVE-2004-0084](https://insights.sbomify.com/CVE-2004-0084/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0284](https://insights.sbomify.com/CVE-2001-0284/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2001-1559 and fix it if it is affected.

What it is: CVE-2001-1559 is a medium-severity vulnerability in Openbsd Openbsd, published on 14 Jul 2005. 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-2001-1559 exists.

Affected product: Openbsd Openbsd. 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-2001-1559/ (Markdown: https://insights.sbomify.com/CVE-2001-1559/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2001-1559
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2001-1559
- OSV: https://osv.dev/vulnerability/CVE-2001-1559

---
From sbomify Insights: https://insights.sbomify.com/CVE-2001-1559/
Summaries are generated and may contain mistakes; the official description above is the record.