# CVE-2016-9180: XML external entity in n/a

> The Perl XML::Twig library fails to disable external entity expansion, allowing attackers to trigger XXE attacks for data disclosure or denial of service.

- **Severity:** Critical 9.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Dec 2016
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-9180, GHSA-6wjc-jvcr-hcxw, SUSE-SU-2020:2172-1, SUSE-SU-2020:2173-1, SUSE-SU-2020:2173-2, UBUNTU-CVE-2016-9180, openSUSE-SU-2020:1177-1, openSUSE-SU-2020:1204-1, openSUSE-SU-2024:11164-1

## What is CVE-2016-9180?

CVE-2016-9180 is a critical vulnerability in n/a, published on 22 Dec 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

perl-XML-Twig: The option to `expand_external_ents`, documented as controlling external entity expansion in XML::Twig does not work. External entities are always expanded, regardless of the option's setting.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2016-9180?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `perl-XML-Twig` | SUSE:HPE Helion OpenStack 8 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Module for Basesystem 15 SP1 | All versions | 3.52-3.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 3.52-3.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server 12 SP2-BCL | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server 12 SP2-LTSS | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server 12 SP3-BCL | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server 12 SP4-LTSS | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server for SAP Applications 12 SP2 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server for SAP Applications 12 SP4 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:OpenStack Cloud 7 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:OpenStack Cloud 8 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:OpenStack Cloud 9 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:OpenStack Cloud Crowbar 8 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | SUSE:OpenStack Cloud Crowbar 9 | All versions | 3.44-5.3.1 |
| `perl-XML-Twig` | openSUSE:Leap 15.1 | All versions | 3.52-lp151.3.3.1 |
| `perl-XML-Twig` | openSUSE:Leap 15.2 | All versions | 3.52-lp152.4.3.1 |
| `perl-XML-Twig` | openSUSE:Tumbleweed | All versions | 3.52-2.8 |

Products: Xmltwig Xml-Twig for Perl.

## How do I fix CVE-2016-9180?

Apply the vendor's patch.

## Is CVE-2016-9180 being exploited?

There is no known exploitation of CVE-2016-9180 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9180 and fix it if it is affected.

What it is: CVE-2016-9180 is a critical vulnerability in n/a, published on 22 Dec 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-9180 in the wild and no public exploit code.

Affected product: n/a. 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-2016-9180/ (Markdown: https://insights.sbomify.com/CVE-2016-9180/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9180
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9180
- OSV: https://osv.dev/vulnerability/CVE-2016-9180

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-9180/
Summaries are generated and may contain mistakes; the official description above is the record.