Internet Bug Bounty · Report #2438265
CVE-2024-27281: RCE vulnerability with .rdoc_options in RDoc
Summary
RDoc RCE vulnerability with .rdoc_options
Description An issue was discovered in RDoc 6.3.3 through 6.6.2, as distributed in Ruby 3.x through 3.3.0.
When parsing .rdoc_options (used for configuration in RDoc) as a YAML file, object injection and resultant remote code execution are possible because there are no restrictions on the classes that can be restored.
When loading the documentation cache, object injection and resultant remote code execution are also possible if there were a crafted cache.
We recommend to update the RDoc gem to version 6.6.3.1 or later. In order to ensure compatibility with bundled version in older Ruby series, you may update as follows instead:
For Ruby 3.0 users: Update to rdoc 6.3.4.1 For Ruby 3.1 users: Update to rdoc 6.4.1.1 For Ruby 3.2 users: Update to rdoc 6.5.1.1 You can use gem update rdoc to update it. If you are using bundler, please add gem "rdoc", ">= 6.6.3.1" to your Gemfile.
Note: 6.3.4, 6.4.1, 6.5.1 and 6.6.3 have a incorrect fix. We recommend to upgrade 6.3.4.1, 6.4.1.1, 6.5.1.1 and 6.6.3.1 instead of them.
Full GHSA: https://github.com/advisories/GHSA-592j-995h-p23j
How it was found
I made a report at https://hackerone.com/reports/1187477
https://www.ruby-lang.org/en/news/2024/03/21/rce-rdoc-cve-2024-27281/
An issue was discovered in RDoc 6.3.3 through 6.6.2, as distributed in Ruby 3.x through 3.3.0. When parsing .rdoc_options (used for configuration in RDoc) as a YAML file, object injection and resultant remote code execution are possible because there are no restrictions on the classes that can be restored. When loading the documentation cache, object injection and resultant remote code execution are also possible if there were a crafted cache.
Impact
RCE is possible when the rdoc command is executed for a repository received from the external.