A flaw was found in, Fedora versions of krb5 from 1.16.1 to, including 1.17.x, in the way a Kerberos client could crash the KDC by sending one of the RFC 4556 "enctypes". A remote unauthenticated user could use this flaw to crash the KDC.

An authentication bypass flaw was found in the way krb5's certauth interface before 1.16.1 handled the validation of client certificates. A remote attacker able to communicate with the KDC could potentially use this flaw to impersonate arbitrary principals under rare and erroneous circumstances.

MIT krb5 1.6 or later allows an authenticated kadmin with permission to add principals to an LDAP Kerberos database to cause a denial of service (NULL pointer dereference) or bypass a DN container check by supplying tagged data that is internal to the database module.

MIT krb5 1.6 or later allows an authenticated kadmin with permission to add principals to an LDAP Kerberos database to circumvent a DN containership check by supplying both a "linkdn" and "containerdn" database argument, or by supplying a DN string which is a left extension of a container DN string but is not hierarchically within the container DN.

plugins/preauth/pkinit/pkinit_crypto_openssl.c in MIT Kerberos 5 (aka krb5) through 1.15.2 mishandles Distinguished Name (DN) fields, which allows remote attackers to execute arbitrary code or cause a denial of service (buffer overflow and application crash) in situations involving untrusted X.509 data, related to the get_matching_data and X509_NAME_oneline_ex functions. NOTE: this has security relevance only in use cases outside of the MIT Kerberos distribution, e.g., the use of get_matching_data in KDC certauth plugin code that is specific to Red Hat.

Double free vulnerability in MIT Kerberos 5 (aka krb5) allows attackers to have unspecified impact via vectors involving automatic deletion of security contexts on error.

In MIT Kerberos 5 (aka krb5) 1.7 and later, an authenticated attacker can cause a KDC assertion failure by sending invalid S4U2Self or S4U2Proxy requests.

The validate_as_request function in kdc_util.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.13.6 and 1.4.x before 1.14.3, when restrict_anonymous_to_tgt is enabled, uses an incorrect client data structure, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an S4U2Self request.

The process_db_args function in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c in the LDAP KDB module in kadmind in MIT Kerberos 5 (aka krb5) through 1.13.4 and 1.14.x through 1.14.1 mishandles the DB argument, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted request to modify a principal.

The (1) kadm5_create_principal_3 and (2) kadm5_modify_principal functions in lib/kadm5/srv/svr_principal.c in kadmind in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.4 and 1.14.x before 1.14.1 allow remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) by specifying KADM5_POLICY with a NULL policy name.