The safe_eval function in Ansible before 1.6.4 does not properly restrict the code subset, which allows remote attackers to execute arbitrary code via crafted instructions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-4657.
https://www.openwall.com/lists/oss-security/2014/07/02/2
https://www.openwall.com/lists/oss-security/2014/06/26/30
https://security-tracker.debian.org/tracker/CVE-2014-4678
https://groups.google.com/forum/message/raw?msg=ansible-announce/ieV1vZvcTXU/5Q93ThkY9rIJ
https://github.com/ansible/ansible/commit/5429b85b9f6c2e640074176f36ff05fd5e4d1916