# CVE-2013-6999: Null dereference in n/a

> Local attackers can crash Windows Server 2008 SP2 via a crafted call to win32k.sys, causing a denial of service.

- **Severity:** Medium 4.0 (`AV:L/AC:H/Au:N/C:N/I:N/A:C`)
- **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:** 7 Dec 2013
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-vxrg-v6vf-8c93

## What is CVE-2013-6999?

CVE-2013-6999 is a medium-severity vulnerability in Microsoft Windows Server 2008, published on 7 Dec 2013. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The IsHandleEntrySecure function in win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2008 SP2 does not properly validate the tagPROCESSINFO pW32Job field, which allows local users to cause a denial of service (NULL pointer dereference and system crash) via a crafted NtUserValidateHandleSecure call for an owned object.  NOTE: the vendor reportedly disputes the significance of this report, stating that "it appears to be a local DOS ... we don't consider it a security vulnerability.

## Which versions are affected by CVE-2013-6999?

It affects 1 product.


Products: Microsoft Windows Server 2008.

## How do I fix CVE-2013-6999?

No fix has been published for CVE-2013-6999 yet. Limit exposure of the affected software until one is available.

## Is CVE-2013-6999 being exploited?

There is no known exploitation of CVE-2013-6999 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows Server 2008

- [CVE-2020-1350](https://insights.sbomify.com/CVE-2020-1350/): Microsoft Windows DNS Server Remote Code Execution (critical 10.0, exploited in the wild)
- [CVE-2020-1040](https://insights.sbomify.com/CVE-2020-1040/): Microsoft Hyper-V RemoteFX vGPU Remote Code Execution (critical 9.0, exploited in the wild)
- [CVE-2011-1966](https://insights.sbomify.com/CVE-2011-1966/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-0239](https://insights.sbomify.com/CVE-2010-0239/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-0240](https://insights.sbomify.com/CVE-2010-0240/): Code injection in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-6999 and fix it if it is affected.

What it is: CVE-2013-6999 is a medium-severity vulnerability in Microsoft Windows Server 2008, published on 7 Dec 2013. 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-2013-6999 in the wild and no public exploit code.

Affected product: Microsoft Windows Server 2008. 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-2013-6999/ (Markdown: https://insights.sbomify.com/CVE-2013-6999/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-6999
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-6999
- OSV: https://osv.dev/vulnerability/CVE-2013-6999

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-6999/
Summaries are generated and may contain mistakes; the official description above is the record.