# CVE-2008-4934: Null dereference in n/a

> Attackers can crash the Linux kernel by mounting a crafted HFS+ filesystem image due to unchecked return values in block allocation.

- **Severity:** High 7.8 (`AV:N/AC:L/Au:N/C:N/I:N/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 5 Nov 2008
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-5hf7-wh5w-w87p

## What is CVE-2008-4934?

CVE-2008-4934 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 5 Nov 2008. 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

The hfsplus_block_allocate function in fs/hfsplus/bitmap.c in the Linux kernel before 2.6.28-rc1 does not check a certain return value from the read_mapping_page function before calling kmap, which allows attackers to cause a denial of service (system crash) via a crafted hfsplus filesystem image.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2008-4934?

It affects 3 products.


Products: Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel.

## How do I fix CVE-2008-4934?

Upgrade to a fixed version.

## Is CVE-2008-4934 being exploited?

There is no known exploitation of CVE-2008-4934 in the wild and no public exploit code.

## 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-2008-4934 and fix it if it is affected.

What it is: CVE-2008-4934 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 5 Nov 2008. 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: There is no known exploitation of CVE-2008-4934 in the wild and no public exploit code.

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-2008-4934/ (Markdown: https://insights.sbomify.com/CVE-2008-4934/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2008-4934
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2008-4934
- OSV: https://osv.dev/vulnerability/CVE-2008-4934

---
From sbomify Insights: https://insights.sbomify.com/CVE-2008-4934/
Summaries are generated and may contain mistakes; the official description above is the record.