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We should backport this commit, potentially in a slightly modified verification so that it can be turned of by a file /etc (for increased backwards compatibility):

commit db3476aff19b75c4fdefbe65fcd5f0a90588ba51
Author: Florian Weimer <fweimer>
Date:   Thu Jun 23 20:01:40 2016 +0200

    libio: Implement vtable verification [BZ #20191]

This blocks a publicly documented exploitation techniques which achieves arbitrary code execution through function pointers used by libio to implemented stdio streams.

Security work in rhel-7 is very important and we will be enabling this in rhel-7.4.

CVE work took precedence over this in our review of rhel-7.4 work. Thus this bug did not make the cut for rhel-7.4. We will review this again as the rhel-7.4 development process progresses and evaluate if we have capacity to complete this work.

Given scheduling and capacity I'm moving this to rhel-7.6. We will get other security enhancements in place for rhel-7.5. Or we will come back to this if we have time.

*** This bug has been marked as a duplicate of bug 1398413 ***