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 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.

MIT Kerberos 5 (aka krb5) through 1.13.1 incorrectly expects that a krb5_read_message data field is represented as a string ending with a '\0' character, which allows remote attackers to (1) cause a denial of service (NULL pointer dereference) via a zero-byte version string or (2) cause a denial of service (out-of-bounds read) by omitting the '\0' character, related to appl/user_user/server.c and lib/krb5/krb/recvauth.c.

The krb5_gss_process_context_token function in lib/gssapi/krb5/process_context_token.c in the libgssapi_krb5 library in MIT Kerberos 5 (aka krb5) through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 does not properly maintain security-context handles, which allows remote authenticated users to cause a denial of service (use-after-free and double free, and daemon crash) or possibly execute arbitrary code via crafted GSSAPI traffic, as demonstrated by traffic to kadmind.

The auth_gssapi_unwrap_data function in lib/rpc/auth_gssapi_misc.c in MIT Kerberos 5 (aka krb5) through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 does not properly handle partial XDR deserialization, which allows remote authenticated users to cause a denial of service (use-after-free and double free, and daemon crash) or possibly execute arbitrary code via malformed XDR data, as demonstrated by data sent to kadmind.

The check_rpcsec_auth function in kadmin/server/kadm_rpc_svc.c in kadmind in MIT Kerberos 5 (aka krb5) through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 allows remote authenticated users to bypass a kadmin/* authorization check and obtain administrative access by leveraging access to a two-component principal with an initial "kadmind" substring, as demonstrated by a "ka/x" principal.

The svcauth_gss_accept_sec_context function in lib/rpc/svc_auth_gss.c in MIT Kerberos 5 (aka krb5) 1.11.x through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 transmits uninitialized interposer data to clients, which allows remote attackers to obtain sensitive information from process heap memory by sniffing the network for data in a handle field.

Double free vulnerability in the init_ctx_reselect function in the SPNEGO initiator in lib/gssapi/spnego/spnego_mech.c in MIT Kerberos 5 (aka krb5) 1.10.x through 1.12.x before 1.12.2 allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via network traffic that appears to come from an intended acceptor, but specifies a security mechanism different from the one proposed by the initiator.

Off-by-one error in the krb5_encode_krbsecretkey function in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c in the LDAP KDB module in kadmind in MIT Kerberos 5 (aka krb5) 1.6.x through 1.11.x before 1.11.6 and 1.12.x before 1.12.2 allows remote authenticated users to cause a denial of service (buffer overflow) or possibly execute arbitrary code via a series of "cpw -keepold" commands.

The acc_ctx_cont function in the SPNEGO acceptor in lib/gssapi/spnego/spnego_mech.c in MIT Kerberos 5 (aka krb5) 1.5.x through 1.12.x before 1.12.2 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via an empty continuation token at a certain point during a SPNEGO negotiation.