Many network configuration services automatically put name servers into /etc/resolv.conf, which is then automatically read by c-ares, and applications using c-ares blindly trust the AD flag even though it doesn't come from a local (or otherwise trusted) resolver.
Working on it, assigning to myself for now.
Created attachment 957732 [details] a patch to clear AD flag unless the nameservers are read from /etc/resolve-secure.conf The attached patch implements one of the ways to handle the difference between trusted and untrusted resolvers. Patched c-ares first attempts to read /etc/resolv-secure.conf for trusted resolver configuration. If that's missing, it reads /etc/resolv.conf as usual but clears the AD flag from any response. There have been other proposals like a directive to list trusted resolvers in the good old /etc/resolv.conf.
Created attachment 957960 [details] a simplified version of the patch, also handling the AD flag setting
This bug appears to have been reported against 'rawhide' during the Fedora 22 development cycle. Changing version to '22'. More information and reason for this action is here: https://fedoraproject.org/wiki/Fedora_Program_Management/HouseKeeping/Fedora22
Dropping RHEL bug from block list.
Fedora 22 changed to end-of-life (EOL) status on 2016-07-19. Fedora 22 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.