Internet Bug Bounty: ReDoS( Ruby, Time)

I reported at https://hackerone.com/reports/1485501

https://www.ruby-lang.org/en/news/2023/03/30/redos-in-time-cve-2023-28756/
> The Time parser mishandles invalid strings that have specific characters. It causes an increase in execution time for parsing strings to Time objects.
> A ReDoS issue was discovered in the Time gem 0.1.0 and 0.2.1 and Time library of Ruby 2.7.7.

Impact

ReDoS occurs when Time.rfc2822 accepts user input.

In Rack::ConditionalGet, the header value is parsed by Time.rfc2822, it is possible to attack from the request.
Rails uses ::Rack::ConditionalGet by default, it can be attacked by a request from the client.