CVE-2020-36327
Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 sometimes chooses a dependency source based on the highest gem version number, which means that a rogue gem found at a public source may be chosen, even if the intended choice was a private gem that…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (6.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 sometimes chooses a dependency source based on the highest gem version number, which means that a rogue gem found at a public source may be chosen, even if the intended choice was a private gem that is a dependency of another private gem that is explicitly depended on by the application. NOTE: it is not correct to use CVE-2021-24105 for every "Dependency Confusion" issue in every product.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 6.31% probability · 94th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- bundler/bundler · fedoraproject/fedora · microsoft/package manager configurations
- Source
- cve@mitre.org
EPSS 6.3% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bundler.io/blog/2021/02/15/a-more-secure-bundler-we-fixed-our-source-priorities.htmlVendor Advisory
- https://github.com/rubygems/rubygems/issues/3982Exploit, Issue Tracking, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL/
- https://mensfeld.pl/2021/02/rubygems-dependency-confusion-attack-side-of-things/Third Party Advisory
- https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-24105Patch, Vendor Advisory
- https://www.zofrex.com/blog/2021/04/29/bundler-still-vulnerable-dependency-confusion-cve-2020-36327/Exploit, Third Party Advisory
- https://bundler.io/blog/2021/02/15/a-more-secure-bundler-we-fixed-our-source-priorities.htmlVendor Advisory
- https://github.com/rubygems/rubygems/issues/3982Exploit, Issue Tracking, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL/
- https://mensfeld.pl/2021/02/rubygems-dependency-confusion-attack-side-of-things/Third Party Advisory
- https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-24105Patch, Vendor Advisory
- https://www.zofrex.com/blog/2021/04/29/bundler-still-vulnerable-dependency-confusion-cve-2020-36327/Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.