# CVE-2009-2698: Null dereference in n/a

> Local attackers can exploit a NULL pointer dereference in the Linux kernel UDP implementation to gain privileges or crash the system.

- **Severity:** High 7.8 (`CVSS:3.1/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:** 27 Aug 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-x9j9-wxm6-8cvm

## What is CVE-2009-2698?

CVE-2009-2698 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 27 Aug 2009. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The udp_sendmsg function in the UDP implementation in (1) net/ipv4/udp.c and (2) net/ipv6/udp.c in the Linux kernel before 2.6.19 allows local users to gain privileges or cause a denial of service (NULL pointer dereference and system crash) via vectors involving the MSG_MORE flag and a UDP socket.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2009-2698?

It affects 12 products.


Products: Canonical Ubuntu Linux, Fedoraproject Fedora, Linux kernel, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Eus, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Workstation, Suse Linux Enterprise Desktop, Suse Linux Enterprise Server, Vmware Esxi, Vmware Vcenter Server.

## How do I fix CVE-2009-2698?

Apply the vendor's patch.

## Is CVE-2009-2698 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-2698 exists.

Public exploit code:

- CVE-2009-2698 compiled for CentOS 4.8 (github_poc): https://github.com/xiaoxiaoleo/CVE-2009-2698
- Linux Kernel 2.6 < 2.6.19 (White Box 4 / CentOS 4.4/4.5 / Fedora Core 4/5/6 x86) - 'ip_append_data()' Ring0 Privilege Escalation (1) (exploitdb)
- Linux Kernel < 2.6.19 (x86/x64) - 'udp_sendmsg' Local Privilege Escalation (2) (exploitdb)
- Linux Kernel < 2.6.19 (Debian 4) - 'udp_sendmsg' Local Privilege Escalation (3) (exploitdb)

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-2698 and fix it if it is affected.

What it is: CVE-2009-2698 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 27 Aug 2009. 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-2009-2698 exists.

Affected product: Canonical Ubuntu Linux. 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-2009-2698/ (Markdown: https://insights.sbomify.com/CVE-2009-2698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-2698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-2698
- OSV: https://osv.dev/vulnerability/CVE-2009-2698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-2698/
Summaries are generated and may contain mistakes; the official description above is the record.