Several vulnerabilities have been found in the MIT reference implementation of Kerberos V5, a system for authenticating users and services on a network. The Common Vulnerabilities and Exposures project identified the following problems: The Apple Product Security team discovered that the SPNEGO GSS-API mechanism suffers of a missing bounds check when reading a network input buffer which results in an invalid read crashing the application or possibly leaking information. Under certain conditions the SPNEGO GSS-API mechanism references a null pointer which crashes the application using the library. An incorrect length check inside the ASN.1 decoder of the MIT krb5 implementation allows an unauthenticated remote attacker to crash of the kinit or KDC program. Under certain conditions the the ASN.1 decoder of the MIT krb5 implementation frees an uninitialized pointer which could lead to denial of service and possibly arbitrary code execution.