Puma used with Rails may lead to Information Exposure

Open Source Vulnerabilities CVE-2022-23634

Puma is a Ruby/Rack web server built for parallelism. 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. 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. Upgrading to a patched Rails _or_ Puma version fixes the vulnerability.

Open Source Vulnerabilities GHSA-rmj8-8hhh-gv5h

### Impact 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. ### Patches 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. ### Workarounds Upgrade to Rails versions 7.02.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2. The [Rails CVE](https://groups.google.com/g/ruby-security-ann/c/FkTM-_7zSNA/m/K2RiMJBlBAAJ?utm_medium=email&utm_source=footer&pli=1) includes a middleware that can be used instead. ### References * Rails CVE: [CVE-2022-23633](https://groups.google.com/g/ruby-security-ann/c/FkTM-_7zSNA/m/K2RiMJBlBAAJ?utm_medium=email&utm_source=footer&pli=1) ### For more information If you have any questions or comments about this advisory: * Open an issue in [puma](https://github.com/puma/puma) * See our [security policy](https://github.com/puma/puma/security/policy)