Multiple memory leaks in kadmin/server/server_stubs.c in kadmind in MIT Kerberos 5 (aka krb5) before 1.13.4 and 1.14.x before 1.14.1 allow remote authenticated users to cause a denial of service (memory consumption) via a request specifying a NULL principal name.

The xdr_nullstring function in lib/kadm5/kadm_rpc_xdr.c in kadmind in MIT Kerberos 5 (aka krb5) before 1.13.4 and 1.14.x before 1.14.1 does not verify whether '\0' characters exist as expected, which allows remote authenticated users to obtain sensitive information or cause a denial of service (out-of-bounds read) via a crafted string.

The iakerb_gss_export_sec_context function in lib/gssapi/krb5/iakerb.c in MIT Kerberos 5 (aka krb5) 1.14 pre-release 2015-09-14 improperly accesses a certain pointer, which allows remote authenticated users to cause a denial of service (memory corruption) or possibly have unspecified other impact by interacting with an application that calls the gss_export_sec_context function. NOTE: this vulnerability exists because of an incorrect fix for CVE-2015-2696.

The build_principal_va function in lib/krb5/krb/bld_princ.c in MIT Kerberos 5 (aka krb5) before 1.14 allows remote authenticated users to cause a denial of service (out-of-bounds read and KDC crash) via an initial '\0' character in a long realm field within a TGS request.

lib/gssapi/spnego/spnego_mech.c in MIT Kerberos 5 (aka krb5) before 1.14 relies on an inappropriate context handle, which allows remote attackers to cause a denial of service (incorrect pointer read and process crash) via a crafted SPNEGO packet that is mishandled during a gss_inquire_context call.

lib/gssapi/krb5/iakerb.c in MIT Kerberos 5 (aka krb5) before 1.14 relies on an inappropriate context handle, which allows remote attackers to cause a denial of service (incorrect pointer read and process crash) via a crafted IAKERB packet that is mishandled during a gss_inquire_context call.

The kdcpreauth modules in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.2 do not properly track whether a client's request has been validated, which allows remote attackers to bypass an intended preauthentication requirement by providing (1) zero bytes of data or (2) an arbitrary realm name, related to plugins/preauth/otp/main.c and plugins/preauth/pkinit/pkinit_srv.c.

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.