# CVE-2018-1000844: XML External Entity (XXE) vulnerability in Square Retrofit


- **Severity:** Critical 9.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 20 Dec 2018
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-j379-9jr9-w5cq

## What is CVE-2018-1000844?

CVE-2018-1000844 is a critical vulnerability in n/a, published on 20 Dec 2018. 

### Official description

Square Open Source Retrofit version Prior to commit 4a693c5aeeef2be6c7ecf80e7b5ec79f6ab59437 contains a XML External Entity (XXE) vulnerability in JAXB that can result in An attacker could use this to remotely read files from the file system or to perform SSRF.. This vulnerability appears to have been fixed in After commit 4a693c5aeeef2be6c7ecf80e7b5ec79f6ab59437.

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

## Which versions are affected by CVE-2018-1000844?

2 open source packages ship an affected version, including com.squareup.retrofit2:retrofit. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.squareup.retrofit2:retrofit` | Maven | From 2.0.0 | 2.5.0 |
| `com.squareup.retrofit2:retrofit` | Maven | From 2.0.0 | 2.5.0 |

Products: Squareup Retrofit.

## How do I fix CVE-2018-1000844?

Upgrade com.squareup.retrofit2:retrofit to 2.5.0 or later.

## Is CVE-2018-1000844 being exploited?

There is no known exploitation of CVE-2018-1000844 in the wild and no public exploit code.

Public exploit code:

- retrofit with CVE-2018-1000844 (github_poc): https://github.com/epicosy/Retrofit-1

## Other vulnerabilities in n/a

- [CVE-2018-1000850](https://insights.sbomify.com/CVE-2018-1000850/): Directory Traversal vulnerability in Square Retrofit (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1000844 and fix it if it is affected.

What it is: CVE-2018-1000844 is a critical vulnerability in n/a, published on 20 Dec 2018. 
Exploitation: There is no known exploitation of CVE-2018-1000844 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.squareup.retrofit2:retrofit (Maven): affected from 2.0.0; fixed in 2.5.0
- com.squareup.retrofit2:retrofit (Maven): affected from 2.0.0; fixed in 2.5.0

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-2018-1000844/ (Markdown: https://insights.sbomify.com/CVE-2018-1000844/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1000844
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1000844
- OSV: https://osv.dev/vulnerability/CVE-2018-1000844

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1000844/
Summaries are generated and may contain mistakes; the official description above is the record.