The deref_parseCtrl function in servers/slapd/overlays/deref.c in OpenLDAP 2.4.13 through 2.4.40 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via an empty attribute list in a deref control in a search request.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.726
EPSS Ranking 98.7%