# CVE-2016-8734: Denial of service in Apache Subversion

> Attackers can cause denial of service in Apache Subversion via exponential XML entity expansion, consuming excessive CPU or memory resources.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Oct 2017
- **Updated:** 16 Sep 2024
- **Also known as:** DEBIAN-CVE-2016-8734, GHSA-x5mc-4p5h-grh2, MGASA-2017-0009, UBUNTU-CVE-2016-8734

## What is CVE-2016-8734?

CVE-2016-8734 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 16 Oct 2017. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Apache Subversion's mod_dontdothat module and HTTP clients 1.4.0 through 1.8.16, and 1.9.0 through 1.9.4 are vulnerable to a denial-of-service attack caused by exponential XML entity expansion. The attack can cause the targeted process to consume an excessive amount of CPU resources or memory.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2016-8734?

It affects 2 products.


Products: Apache Subversion, Debian Debian Linux.

## How do I fix CVE-2016-8734?

Upgrade to a fixed version.

## Is CVE-2016-8734 being exploited?

There is no known exploitation of CVE-2016-8734 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2017-9800](https://insights.sbomify.com/CVE-2017-9800/): A maliciously constructed svn+ssh:// URL would cause Subversion clients before 1.8.19, 1.9.x before 1.9.7, and 1.10.0.x through 1.10.0-alpha (critical 9.8)
- [CVE-2013-4246](https://insights.sbomify.com/CVE-2013-4246/): Denial of service in n/a (high 8.8)
- [CVE-2015-5259](https://insights.sbomify.com/CVE-2015-5259/): Integer overflow in n/a (high 8.6)
- [CVE-2024-45720](https://insights.sbomify.com/CVE-2024-45720/): Apache Subversion: Command line argument injection on Windows platforms (high 8.2)
- [CVE-2015-0202](https://insights.sbomify.com/CVE-2015-0202/): Denial of service in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-8734 and fix it if it is affected.

What it is: CVE-2016-8734 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 16 Oct 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-8734 in the wild and no public exploit code.

Affected product: Debian Debian 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-2016-8734/ (Markdown: https://insights.sbomify.com/CVE-2016-8734/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-8734
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-8734
- OSV: https://osv.dev/vulnerability/CVE-2016-8734

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-8734/
Summaries are generated and may contain mistakes; the official description above is the record.