Is there a mechanism built into rpm or apt that will warn (or prevent) a user from installing a package contains a known security threat?
I'm thinking of an RPM like openssl-1.0.1e-15.el6.x86_64.rpm. Seems odd that it can float out there forever waiting for someone to use it, probably following outdated installation instructions for some offbeat secure software.
Is there a mechanism built into rpm or apt that will warn (or prevent) a user from installing a package contains a known security threat?
No.
Knowing this kind of thing is part of the job of being a professional systems administrator. I don't expect (or want) my tools to spoon-feed me. Nor do I want them to prevent me from doing something destructive if I so desire. You know that quote about power and responsibility? It applies here as well.
openssl-1.0.1e-15.el6was a known security problem forever. In reality, it wasn't known (except for a very small number of people, like the people who discovered it, the engineers who fixed it; and perhaps other organizations who have the money and resources to analyze openssl at a fine detail) until a few days ago. Once a threat is "known", in the public sense, yes there are tools to help the sysadmin.portauditon FreeBSD,yum-securityon RHEL, etc.