Prior to puma
version 5.6.2
, puma
may not always call close
on the response body. Rails, prior to version 7.0.2.2
, depended on the response body being closed in order for its CurrentAttributes
implementation to work correctly.
From Rails:
Under certain circumstances response bodies will not be closed, for example a bug in a webserver[1] or a bug in a Rack middleware. In the event a response is not notified of a close, ActionDispatch::Executor will not know to reset thread local state for the next request. This can lead to data being leaked to subsequent requests, especially when interacting with ActiveSupport::CurrentAttributes.
The combination of these two behaviors (Puma not closing the body + Rails' Executor implementation) causes information leakage.
This problem is fixed in Puma versions 5.6.2 and 4.3.11.
This problem is fixed in Rails versions 7.02.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2.
See: https://github.com/advisories/GHSA-wh98-p28r-vrc9 for details about the rails vulnerability
Upgrading to a patched Rails or Puma version fixes the vulnerability.
Upgrade to Rails versions 7.02.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2.
The Rails CVE includes a middleware that can be used instead.
If you have any questions or comments about this advisory: * Open an issue in puma * See our security policy