# Dependency Confusion in Bundler

Advisory record · `GHSA-fp4w-jxhp-m23p`

- **Identifiers:** `GHSA-fp4w-jxhp-m23p` · `CVE-2020-36327`
- **State:** Confirmed
- **Severity:** CVSS 8.8 High
- **Critical:** No
- **Published:** 24 May 2021
- **Updated:** 5 Dec 2024
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 24 May 2021, 18:12 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `bundler` (RubyGems): affected `>=1.16.0, <2.2.10 || >=2.2.11, <2.2.18`; fixed in `2.2.10`, `2.2.18`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.8 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.063, the 93rd percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 24 May 2021. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-fp4w-jxhp-m23p](https://github.com/advisories/GHSA-fp4w-jxhp-m23p)
- [OSV: GHSA-fp4w-jxhp-m23p](https://osv.dev/vulnerability/GHSA-fp4w-jxhp-m23p)
- <https://nvd.nist.gov/vuln/detail/CVE-2020-36327>
- <https://github.com/rubygems/rubygems/issues/3982>
- <https://github.com/rubygems/rubygems/pull/4609>
- <https://github.com/rubygems/rubygems/commit/078bf682ac40017b309b5fc69f283ff640e7c129>
- <https://bundler.io/blog/2021/02/15/a-more-secure-bundler-we-fixed-our-source-priorities.html>
- <https://github.com/rubygems/rubygems>
- <https://github.com/rubygems/rubygems/blob/master/bundler/CHANGELOG.md#2218-may-25-2021>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/bundler/CVE-2020-36327.yml>
- <https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL>
- <https://mensfeld.pl/2021/02/rubygems-dependency-confusion-attack-side-of-things>
- <https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-24105>
- <https://www.zofrex.com/blog/2021/04/29/bundler-still-vulnerable-dependency-confusion-cve-2020-36327>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-fp4w-jxhp-m23p>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-fp4w-jxhp-m23p/>. Everything for agents: <https://agentprime.io/llms.txt>.