SB2021080910 - Remote code execution in Bundler
Published: August 9, 2021
Security Bulletin ID
SB2021080910
Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Insufficient verification of data authenticity (CVE-ID: CVE-2020-36327)
The vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to insufficient verification of data authenticity in Bundler, when choosing a dependency source. The application selects 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.
Remediation
Install update from vendor's website.
References
- https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-24105
- https://github.com/rubygems/rubygems/issues/3982
- https://bundler.io/blog/2021/02/15/a-more-secure-bundler-we-fixed-our-source-priorities.html
- https://mensfeld.pl/2021/02/rubygems-dependency-confusion-attack-side-of-things/
- https://www.zofrex.com/blog/2021/04/29/bundler-still-vulnerable-dependency-confusion-cve-2020-36327/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL/