ADVISORIES
GEM
SEVERITY
CVSS v3.x: 8.0 (High)
PATCHED VERSIONS
- ~> 4.3.11
- >= 5.6.2
DESCRIPTION
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 7.0.2.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2.
The Rails CVE includes a middleware that can be used instead.