# CVE-2009-2958: Null dereference in n/a

> Remote attackers can crash the dnsmasq daemon via a malformed TFTP request when TFTP support is enabled.

- **Severity:** Medium 4.3 (`AV:N/AC:M/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:** Yes
- **Published:** 2 Sep 2009
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2009-2958, GHSA-m4qp-3gf5-73rm

## What is CVE-2009-2958?

CVE-2009-2958 is a medium-severity vulnerability in n/a, published on 2 Sep 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The tftp_request function in tftp.c in dnsmasq before 2.50, when --enable-tftp is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a TFTP read (aka RRQ) request with a malformed blksize option.

Weakness: CWE-399

## Which versions are affected by CVE-2009-2958?

It affects 1 product.


Products: Thekelleys Dnsmasq.

## How do I fix CVE-2009-2958?

Upgrade to a fixed version.

## Is CVE-2009-2958 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-2958 exists.

Public exploit code:

- Dnsmasq < 2.50 - Heap Overflow / Null Pointer Dereference (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2021-45951](https://insights.sbomify.com/CVE-2021-45951/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-45952](https://insights.sbomify.com/CVE-2021-45952/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-45953](https://insights.sbomify.com/CVE-2021-45953/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-45954](https://insights.sbomify.com/CVE-2021-45954/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-45955](https://insights.sbomify.com/CVE-2021-45955/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-2958 and fix it if it is affected.

What it is: CVE-2009-2958 is a medium-severity vulnerability in n/a, published on 2 Sep 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-2958 exists.

Affected product: n/a. 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-2009-2958/ (Markdown: https://insights.sbomify.com/CVE-2009-2958/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-2958
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-2958
- OSV: https://osv.dev/vulnerability/CVE-2009-2958

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-2958/
Summaries are generated and may contain mistakes; the official description above is the record.