# CVE-2018-1000850: Directory Traversal vulnerability in Square Retrofit

> Attackers can manipulate URL path parameters to add or delete resources via directory traversal in the Retrofit HTTP client library.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Dec 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-8p8g-f9vg-r7xr

## What is CVE-2018-1000850?

CVE-2018-1000850 is a high-severity path traversal vulnerability in n/a, published on 20 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Square Retrofit version versions from (including) 2.0 and 2.5.0 (excluding) contains a Directory Traversal vulnerability in RequestBuilder class, method addPathParameter that can result in By manipulating the URL an attacker could add or delete resources otherwise unavailable to her.. This attack appear to be exploitable via An attacker should have access to an encoded path parameter on POST, PUT or DELETE request.. This vulnerability appears to have been fixed in 2.5.0 and later.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2018-1000850?

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-2018-1000850?

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

## Is CVE-2018-1000850 being exploited?

There is no known exploitation of CVE-2018-1000850 in the wild and no public exploit code.

Public exploit code:

- https://github.com/shoucheng3/square__retrofit_CVE-2018-1000850_2-4-0 (github_poc): https://github.com/shoucheng3/square__retrofit_CVE-2018-1000850_2-4-0

## Other vulnerabilities in n/a

- [CVE-2018-1000844](https://insights.sbomify.com/CVE-2018-1000844/): XML External Entity (XXE) vulnerability in Square Retrofit (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1000850 and fix it if it is affected.

What it is: CVE-2018-1000850 is a high-severity path traversal vulnerability in n/a, published on 20 Dec 2018. 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-2018-1000850 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-2018-1000850/ (Markdown: https://insights.sbomify.com/CVE-2018-1000850/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1000850
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1000850
- OSV: https://osv.dev/vulnerability/CVE-2018-1000850

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1000850/
Summaries are generated and may contain mistakes; the official description above is the record.