Hi, Before enrolling new fingerprints a password should be requested. Otherwise it could lead to privileges escalation like the one described in: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=719004 if for example the laptop is not locked and left unattended. Even if the PAM module is not added to sudo/su/... PAM services, this could lead to some attacker changing one of the login method of a user and allowing him to login later.
*** This bug has been marked as a duplicate of bug 89407 ***
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