ADVISORIES
GEM
SEVERITY
CVSS v3.x: 6.3 (Medium)
PATCHED VERSIONS
- >= 2.8.0
DESCRIPTION
Impact
better_errors prior to 2.8.0 did not implement CSRF protection for its internal requests. It also did not enforce the correct "Content-Type" header for these requests, which allowed a cross-origin "simple request" to be made without CORS protection. These together left an application with better_errors enabled open to cross-origin attacks.
As a developer tool, better_errors documentation strongly recommends addition only to the development bundle group, so this vulnerability should only affect development environments. Please ensure that your project limits better_errors to the development group (or the non-Rails equivalent).
Patches
Starting with release 2.8.x, CSRF protection is enforced. It is recommended that you upgrade to the latest release, or minimally to "~> 2.8.3".
Workarounds
There are no known workarounds to mitigate the risk of using older releases of better_errors.
References
- Chris Moberly provided an example attack that uses a now-patched vulnerability of webpack-dev-server in conjunction with Better Errors
For more information
If you have any questions or comments about this advisory, please
- Add to the discussion in better_errors
- Open an issue in better_errors