Versions mentioned in the description apply to the upstream
Remediation section below for
Debian:10 relevant versions.
ec_verify in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.4 and 1.19.x before 1.19.2 allows remote attackers to cause a NULL pointer dereference and daemon crash. This occurs because a return value is not properly managed in a certain situation.
krb5 to version 1.17-3+deb10u2 or higher.