Redux Framework < 4.5.13 - Subscriber+ Privilege Escalation to Administrator

The Redux Framework WordPress plugin before 4.5.13 does not restrict which user meta keys can be written when saving custom profile fields, allowing users with at least the Subscriber role to escalate their privileges to Administrator by submitting a crafted value while updating their own profile, on sites where the Redux Framework WordPress plugin before 4.5.13's user-profile (Users extension) feature is enabled.