Executive brief
Ruby on Rails, a popular framework for building web applications, contains a security flaw that allows unauthorized individuals to view sensitive files on the server. By sending a specially crafted request, an attacker can bypass security restrictions to read configuration files, source code, or other private data. This vulnerability has been observed being used in active attacks and could lead to the exposure of confidential business information.
Technical details
A path traversal vulnerability exists in the Action View component of Ruby on Rails. The flaw is triggered when an application uses the `render file:` method in a way that interacts with user-supplied Accept headers. An unauthenticated remote attacker can provide a specially crafted Accept header to escape the intended directory and read arbitrary files from the server's filesystem. This vulnerability has been confirmed to be exploited in the wild and is addressed in versions 5.2.2.1, 5.1.6.2, 5.0.7.2, and 4.2.11.1.
Affected products
- Ruby on Rails Ruby on Rails < 5.2.2.1, < 5.1.6.2, < 5.0.7.2, < 4.2.11.1, v3
Timeline
- 2019-03-13: patched: Vendor released security updates for multiple versions
- 2019-03-22: disclosed: Public disclosure of the vulnerability details
- 2025-07-07: kev added: Added to CISA Known Exploited Vulnerabilities catalog