RubyGems version 2.6.12 and earlier is vulnerable to a DNS hijacking vulnerability that allows a MITM attacker to force the RubyGems client to download and install gems from a server that the attacker controls.
- https://github.com/rubygems/rubygems/commit/8d91516fb7037ecfb27622f605dc40245e0f8d32
- https://hackerone.com/reports/218088
- https://github.com/ARPSyndicate/cvemon