schpw.c in the kpasswd service in kadmind in MIT Kerberos 5 (aka krb5) before 1.11.3 does not properly validate UDP packets before sending responses, which allows remote attackers to cause a denial of service (CPU and bandwidth consumption) via a forged packet that triggers a communication loop, as demonstrated by krb_pingpong.nasl, a related issue to CVE-1999-0103.

The prep_reprocess_req function in do_tgs_req.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.5 does not properly perform service-principal realm referral, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted TGS-REQ request.

The pkinit_check_kdc_pkid function in plugins/preauth/pkinit/pkinit_crypto_openssl.c in the PKINIT implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.4 and 1.11.x before 1.11.1 does not properly handle errors during extraction of fields from an X.509 certificate, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a malformed KRB5_PADATA_PK_AS_REQ AS-REQ request.

The pkinit_server_return_padata function in plugins/preauth/pkinit/pkinit_srv.c in the PKINIT implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.4 attempts to find an agility KDF identifier in inappropriate circumstances, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted Draft 9 request.

The kdc_handle_protected_negotiation function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8.x, 1.9.x before 1.9.5, and 1.10.x before 1.10.3 attempts to calculate a checksum before verifying that the key type is appropriate for a checksum, which allows remote attackers to execute arbitrary code or cause a denial of service (uninitialized pointer free, heap memory corruption, and daemon crash) via a crafted AS-REQ request.

The process_as_req function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.10.x before 1.10.3 does not initialize a certain structure member, which allows remote attackers to cause a denial of service (uninitialized pointer dereference and daemon crash) or possibly execute arbitrary code via a malformed AS-REQ request.

The check_1_6_dummy function in lib/kadm5/srv/svr_principal.c in kadmind in MIT Kerberos 5 (aka krb5) 1.8.x, 1.9.x, and 1.10.x before 1.10.2 allows remote authenticated administrators to cause a denial of service (NULL pointer dereference and daemon crash) via a KRB5_KDB_DISALLOW_ALL_TIX create request that lacks a password.

server/server_stubs.c in the kadmin protocol implementation in MIT Kerberos 5 (aka krb5) 1.10 before 1.10.1 does not properly restrict access to (1) SET_STRING and (2) GET_STRINGS operations, which might allow remote authenticated administrators to modify or read string attributes by leveraging the global list privilege.

The process_tgs_req function in do_tgs_req.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.9 through 1.9.2 allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted TGS request that triggers an error other than the KRB5_KDB_NOENTRY error.

The krb5_ldap_lockout_audit function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8 through 1.8.4 and 1.9 through 1.9.1, when the LDAP back end is used, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors, related to the locked_check_p function. NOTE: the Berkeley DB vector is covered by CVE-2011-4151.