A flaw was discovered in OpenLDAP before 2.4.57 leading to a memch->bv_len miscalculation and slapd crash in the saslAuthzTo processing, resulting in denial of service.
https://www.debian.org/security/2021/dsa-4845
https://support.apple.com/kb/HT212531
https://support.apple.com/kb/HT212530
https://support.apple.com/kb/HT212529
https://security.netapp.com/advisory/ntap-20210226-0002/
https://lists.debian.org/debian-lts-announce/2021/02/msg00005.html
https://git.openldap.org/openldap/openldap/-/tags/OPENLDAP_REL_ENG_2_4_57
https://git.openldap.org/openldap/openldap/-/commit/d169e7958a3e0dc70f59c8374bf8a59833b7bdd8
https://git.openldap.org/openldap/openldap/-/commit/c0b61a9486508e5202aa2e0cfb68c9813731b439
https://git.openldap.org/openldap/openldap/-/commit/5a2017d4e61a6ddc4dcb4415028e0d08eb6bca26
https://git.openldap.org/openldap/openldap/-/commit/554dff1927176579d652f2fe60c90e9abbad4c65
https://bugs.openldap.org/show_bug.cgi?id=9413
http://seclists.org/fulldisclosure/2021/May/70