Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
From VID-CE6DB19B-976E-11EA-93C4-08002728F74C:
Ruby on Rails blog:
Due to an unfortunate oversight, Rails 4.2.11.2 has a missing constant
error. To address this Rails 4.2.11.3 has been released.
The original announcement for CVE-2020-8163 has a follow-up message
with an updated patch if you’re unable to use the gems.
With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.
– Scott Cheney, Manager of Information Security, Sierra View Medical Center