# CVE-2008-4409: Denial of service in n/a

> Attackers can cause denial of service via memory consumption and crashes by providing malicious XML documents to applications using libxml2.

- **Severity:** Medium 5.0 (`AV:N/AC:L/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 3 Oct 2008
- **Updated:** 7 Aug 2024
- **Also known as:** CVE-2008-4422, GHSA-34h5-p5c9-pjw6

## What is CVE-2008-4409?

CVE-2008-4409 is a medium-severity denial of service vulnerability in Xmlsoft Libxml2, published on 3 Oct 2008. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

libxml2 2.7.0 and 2.7.1 does not properly handle "predefined entities definitions" in entities, which allows context-dependent attackers to cause a denial of service (memory consumption and application crash), as demonstrated by use of xmllint on a certain XML document, a different vulnerability than CVE-2003-1564 and CVE-2008-3281.

Weakness: CWE-399

## Which versions are affected by CVE-2008-4409?

It affects 1 product.


Products: Xmlsoft Libxml2.

## How do I fix CVE-2008-4409?

Upgrade to a fixed version.

## Is CVE-2008-4409 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2008-4409 exists.

Public exploit code:

- libxml2 - Denial of Service (exploitdb)

## Other vulnerabilities in Xmlsoft Libxml2

- [CVE-2017-16931](https://insights.sbomify.com/CVE-2017-16931/): XML external entity in n/a (critical 9.8)
- [CVE-2017-8872](https://insights.sbomify.com/CVE-2017-8872/): Information disclosure in n/a (critical 9.1)
- [CVE-2022-49043](https://insights.sbomify.com/CVE-2022-49043/): Use after free in libxml2 (high 8.1)
- [CVE-2026-86140](https://insights.sbomify.com/CVE-2026-86140/): Memory corruption in libxml2 (high 8.0)
- [CVE-2024-34459](https://insights.sbomify.com/CVE-2024-34459/): Memory corruption in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2008-4409 and fix it if it is affected.

What it is: CVE-2008-4409 is a medium-severity denial of service vulnerability in Xmlsoft Libxml2, published on 3 Oct 2008. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2008-4409 exists.

Affected product: Xmlsoft Libxml2. 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-2008-4409/ (Markdown: https://insights.sbomify.com/CVE-2008-4409/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2008-4409
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2008-4409
- OSV: https://osv.dev/vulnerability/CVE-2008-4409

---
From sbomify Insights: https://insights.sbomify.com/CVE-2008-4409/
Summaries are generated and may contain mistakes; the official description above is the record.