It was discovered that the Key Distribution Center (KDC) in krb5, the
MIT implementation of Kerberos, is prone to a NULL pointer dereference
flaw. An unauthenticated attacker can take advantage of this flaw to
cause a denial of service (KDC crash) by sending a request containing a PA-ENCRYPTED-CHALLENGE padata element without using FAST.
For the stable distribution (buster), this problem has been fixed in