The ipapwd_chpwop function in daemons/ipa-slapi-plugins/ipa-pwd-extop/ipa_pwd_extop.c in the directory server (dirsrv) in FreeIPA before 3.2.0 allows remote attackers to cause a denial of service (crash) via a connection request without a username/dn, related to the 389 directory server.
https://fedorahosted.org/freeipa/ticket/3539
https://exchange.xforce.ibmcloud.com/vulnerabilities/83132
https://bugzilla.redhat.com/show_bug.cgi?id=913751